New synthesis of tic-hydantoins sigma-1 ligands and pharmacological evaluation on cocaine-induced stimulant effects

Medicinal Chemistry, 2010, 6, 355-373

355

New Synthesis of Tic-Hydantoins Sigma-1 Ligands and Pharmacological

Evaluation on Cocaine-Induced Stimulant Effects

M. Toussaint^1,2, M.-A. Debreu-Fontaine^1,2,3, T. Maurice^4,5,6and P. Melnyk^1,2,3*

¹CNRS UMR 8161, F-59021 Lille, France; ²Univ Lille Nord de France, F-59000 Lille, France; ³UDSL, EA

4

5

4481GRIIOT, UFR Pharmacie, F-59000 Lille, France; INSERM U 710, 34095 Montpellier, France; University of

Montpellier 2, 34095 Montpellier, France; ⁶EPHE, 75017 Paris, France

Abstract: Activation of the newly identified ꢀ₁chaperone protein is involved in several aspects of the psychostimulant

and addictive effects of cocaine. The development of ligands that selectively target the ꢀ₁protein may lead to putative po-

tent anti-cocaine agents. We report here a new and more convergent synthetic pathway to amino side chain substituted

hydantoins. Twenty new analogs of our lead compound were synthesized. None of them showed better in vitro affinity for

ꢀ₁receptor than our lead compound. Nevertheless, three of them, obtained as racemates, showed high in vitro affinity and

selectivity for ꢀ₁receptor. A preliminary in vivo evaluation of their pharmacological activity identified compound 22 as

one that increases cocaine-induced locomotor stimulation and therefore acts as a potential efficient ꢀ₁agonist.

Keywords: ꢀ₁protein, agonist, hydantoin, isoquinoline, cocaine, addiction.

1. INTRODUCTION

lethality locomotion activity and rewarding in mice [12-19].

Finally, ꢀ₁receptors can modulate the activity of other neu-

rotransmitter systems such as dopamine [20, 21] and sero-

tonin [22, 23], that are relevant to the actions of cocaine.

While cocaine abuse remains a major public health prob-

lem, there are presently no effective medications to aid in its

treatment [1]. Cocaine, a highly addictive substance, pro-

duces its toxic, physiological and behavioural effects through

its interactions with several different sites of the central

nervous system (CNS). It acts as a dopamine, serotonine and

noradrenaline reuptake inhibitor and binds numerous recep-

tors, including muscarinic and ꢀ receptors. Acute administra-

tion of cocaine induces hyperlocomotion and stereotypies,

whereas repeated administration provokes sensitisation to the

drug effects, with reinforcement and dependence appearing

within a short time after the first administration [2]. Evi-

dence supporting the involvement of ꢀ proteins in cocaine's

behavioral effects has gained increasing acceptance in recent

years, thus suggesting ꢀ proteins as promising medication

development targets for cocaine abuse [3, 4].

Moreover, cocaine acutely enhances dopamine transmis-

sion and chronically decreases dopamine concentration in the

brain. Consequently, during the initial period of abstinence

after cocaine use, subjects may experience symptoms such

depression, fatigue, irritability, anorexia and sleep distur-

bances. One treatment strategy to counteract these effects

may be to administer agonists. To date, clinical trials and

therapeutic approaches using only dopaminergic transmis-

sion facilitating agents such as dopamine agonists, mono-

amine oxidase (MAO) inhibitors or psychostimulating sub-

stances, have proven to be only mildly effective in reducing

use and associated symptoms like craving [3, 24-26]. Thus,

research into ꢀ₁receptor modulators presents an opportunity

to advance cocaine agonist therapy beyond the limited effec-

tiveness of the current set of treatment strategies.

The ꢀ receptors exist as two established subtypes, ꢀ₁and

ꢀ₂. Whereas ꢀ₁protein has been cloned from various tissues

and species, the ꢀ₂has not yet been cloned, nor its nature

precisely identified [5-8]. The ꢀ ₁receptor is an intracellular

chaperone protein mainly located on endoplasmic reticulum

membranes [9]. Studies of the ꢀ₁receptor indicate its rele-

vancy as a target for the treatment of cocaine abuse for sev-

eral reasons. First, it is located in key organs, like the brain

and the heart, that mediate the drug’s actions [10]. Addition-

aly, cocaine binds both subtypes at in vivo concentrations,

but has approximately a 10-fold greater affinity for ꢀ₁recep-

tors as compared with ꢀ₂receptors [11]. Furthermore, treat-

ment with ꢀ₁antagonists or antisense oligodeoxynucleotides

have been known to prevent cocaine induced convulsions,

Previous studies in our laboratory evidenced the affinity

of compound 1 (IC₅₀(human) = 8.7 nM) toward ꢀ₁(Fig. (1))

with a good selectivity towards ꢀ₂receptor (IC₅₀> 500 nM)

and a very low cytotoxicity, as indicated by a high selectivity

index (ratio CC₅₀/IC₅₀> 50 000). Studies on different behav-

ioral tests show that compound 1 presents a typical profile of

a ꢀ₁protein activator, facilitating cocaine-induced behavioral

effects [27, 28].

Previous structure-activity-relationship (SAR) studies

were performed in our laboratory on the modification of the

tetrahydroisoquinoline hydantoin (Tic-hydantoin) structure

showing that the Tic-hydantoin core represents a key phar-

macophore for the ꢀ₁receptor binding affinity [29]. We also

showed that hit compound 1 and its enantiomer 2 provided

similar in vitro ꢀ₁affinity, ꢀ₂/ꢀ₁selectivity and a similar

agonist profile, though 1 was a little more efficient in vivo

*Address correspondence to this author at the EA 4481GRIIOT, UFR

Pharmacie, 3 rue du Pr Laguesse, 59006 Lille cédex, France; Tel: 33 (0)3 20

96 49 49; E-mail: patricia.melnyk@univ-lille2.fr

1573-4064/10 $55.00+.00

356 Medicinal Chemistry, 2010, Vol. 6, No. 6

Toussaint et al.

O

To compare the SAR of all the series, the same substitu-

ents on the aromatic ring were evaluated. We chose to study

the role of simple or hindered aliphatic substituents (methyl,

tert-butyl), electron withdrawing and donating groups (nitro,

methoxy) and fluoride. For the aliphatic, we studied the im-

pact of methyl, ethyl, isobutyl and cyclohexyl groups.

N

1

O

Fig. (1). Hit compound.

2. CHEMISTRY

than its enantiomer 2. In this paper, we investigated the SAR

studies on the amino side chain starting from the hit com-

pound. In this first study, stereochemistry was not taken into

account. Pharmacomodulation of the structures was imple-

mented in order to study the ꢀ₁pharmacophore and the be-

havioral effects of cocaine within the best candidates. Subse-

quently, a new and more convergent synthesis was settled

starting from racemic 1,2,3,4-tetrahydro-3-isoquinoline-

carboxylic acid and a small library of structural analogs was

made based on the modification of the side chain of the hit

compound (Fig. (2)).

Two methods were investigated for the preparation of the

first series of compounds (3-22). The first method is based

on the synthesis of the aldehyde 37 described in (Scheme 1).

After several essays to optimize the reaction, Tic-hydantoin

35 was prepared by intramolecular cyclisation from 1,2,3,4-

tetrahydro-3-isoquinolinecarboxylic acid in the presence of

potassium isocyanate in DMF. Then, compound 36, after a

treatment with bromoethyldioxolane under basic conditions,

was obtained. After an acidic deprotection, aldehyde 37 was

reacted with appropriate amines [30], previously synthesised

from the corresponding benzylamine derivatives [31], to

afford the compounds 7 and 8.

To understand better the SAR of the series and study the

pharmacophore, we evaluated the importance of the phenyl

ring for the affinity and the specificity toward ꢀ₁receptor.

Thus, several series of compounds were synthesized to study

the impact of this aromatic ring, the small substituent on the

basic nitrogen and the eventual importance of a restricted

conformation on the side chain.

The second method was based on the synthesis of the key

intermediate amine 43 following the protocol described in

Scheme 2. This method started with the synthesis of anhy-

dride 40 which was prepared by successive protection and

cyclisation in the presence of phosphorus trichloride on

1,2,3,4-tetrahydro-3-isoquinolinecarboxylic acid [32].

O

R'

N

R

N

R

N

R''

O

Compounds

R’ =

R” =

Compounds

R =

Ph

Compounds

R =

Ph

1 / 2

3

Me

Et

CH₂-Ph

CH₂-pMe Ph

CH₂-ptBu Ph

CH₂-pOMe Ph Ph

CH₂-pNO₂Ph

CH₂- pF Ph

CH₂-cycloHex

Me

23

24

25

26

27

28

29

30

31

32

33

pMe Ph

ptBu Ph

pMe Ph

4

pOMe Ph

pF Ph

5

pOMe Ph

pNO₂Ph

pF Ph

6

7

8

cycloHex

9

10

11

12

13

14

15

16

17

18

19

20

21

22

Et

iBu

CH₂-Ph

CH₂-pMe Ph

CH₂-ptBu Ph

CH₂-pOMe Ph

CH₂-pNO₂Ph

CH₂-pF Ph

CH₂-cycloHex

Et

CH₂-Ph

CH₂-pMe Ph

CH₂-ptBu Ph

CH₂-pOMe Ph

CH₂-pNO₂Ph

CH₂-pF Ph

CH₂-cycloHex

CH₂-Ph

iBu

CH₂-Ph

isoindolinyl

isoquinolinyl

Fig. (2). Target compounds 3-33 by modification on the side chain.

New Synthesis of Tic-Hydantoins Sigma-1 Ligands and Pharmacological Evaluation

Medicinal Chemistry, 2010, Vol. 6, No. 6 357

O

OH

a

b

c

NH

O

N

NH

N

35

36

O

d

N

H

N

NH

R''

37

O

R''

7 R'' = 4-fluorobenzyl

8 R'' = cyclohexyl

38 R'' = 4-fluorobenzyl

39 R'' = cyclohexyl

Reagents. (a) (i) KOCN, DMF, 70°C, 2h; (ii) HCl, DMF, 70°C, 2h, 70%; (b) bromoethyldioxolane, K₂CO₃, DMF, 70°C, overnight, 70%; (c) HCl 10%,

acetone, rt, 30 min, 100%; (d) NaBH(OAc)₃, AcOH, THF, rt, overnight 37-41%.

Scheme (1). synthesis of compounds 7 and 8.

O

a

OH

O

N

NH

d

N

H

NHBoc

c

40

O

NH₂

N

+

N

NH

b

42

H₂N

NHBoc

H₂N

NH₂

41

43

O

Reagents. (a) (i) Boc₂O, NaOH 1M, dioxane, H₂O, rt, overnight, 96% ; (ii) PCl₃, DCM, 0°C, 2h, 100% ; (b) Boc₂O, CHCl₃/TEA,

reflux, overnight, 93%; (c) DIEA, DCM, rt, overnight, 61%; (d) (i) CDI, DIEA, THF, overnight, 70°C, 77% ; (ii) TFA, DCM, rt, 30 min, 75%.

Scheme (2). Synthesis of intermediate 43.

O

a

b

N

NH₂

NH

N

44

43

OMe

5

O

+

N

O

9

O

c

d

N

Ar

N

Ar

N

Me

N

H

N

O

3

Ar =

45 Ar =

46 Ar =

47 Ar =

4

6

NO₂

Reagents. (a) HCHO 37%, HCOOH, DMF, rt, 2h, 26%; (b) p-methoxybenzaldehyde, NaBH(OAc)₃, CH₃COOH, DCM, rt,

overnight, 94%; (c) ArCHO, NaBH₄, TEA, EtOH, rt, overnight, 30-50%; (d) HCHO, NaBH₃CN, CH₃CN, rt, 15 min, 23-41%.

Scheme (3). Syntehsis of compounds 3, 4, 5, 6, and 9.

In parallel, 1,3-diaminopropane was monoprotected by

dropwise addition of Boc₂O to a solution of 7 equivalents of

the amine in chloroform, at reflux for two hours [33]. Then,

anhydride 40 was coupled with amine 41 to give compound

42. Next, after cyclization in presence of CDI and DIEA,

followed by deprotection with TFA, the key intermediate 43

was obtained (Scheme 2).

mixture of the monomethyl 44 and the dimethyl 9 derivatives

was obtained. Nevertheless, compound 44 was obtained in

sufficient amounts to continue the synthesis via the reductive

amination to afford the methoxy 5.

In order to optimize the synthesis, the reductive amina-

tion in the presence of sodium borohydride was conducted

followed by the methylation. The three compounds, methyl

3, tert-butyl 4 and nitro 6 were prepared following this pro-

cedure [34] (Scheme 3).

Our efforts were next focused on the methylation of

amine 43. Despite trying several conditions, the synthesis of

the monomethyl derivative 44 could not be optimised and a

358 Medicinal Chemistry, 2010, Vol. 6, No. 6

Toussaint et al.

To complete the study, we evaluated then, the importance

of the small substituent (methyl) on the basic nitrogen to

verify that only one hydrophobic group was necessary. The

nitrogen was substituted by two aromatic rings or two ali-

phatic groups. The series of compounds (Scheme 4) were

obtained by reductive amination of amine 43 and the corre-

sponding commercially available aldehydes.

The piperidine series was synthesized from 1,2,3,4-

tetrahydro-3-isoquinolinecarboxylic acid. It was first pro-

tected with a tert-butylcarbonate group followed by coupling

with 4-amino-1-benzylpiperidine in the presence of HOBt

and HBTU to give compound 49. After deprotection and

intramolecular cyclization with CDI under basic conditions,

compound 23, first compound of the family and key inter-

mediate, was obtained. Deprotection of the amine using Pd/C

and ammonium formate afforded the amine 50 [36]. Finally,

the amine 50 reacted on the corresponding commercially

available aldehyde to give the target compounds 24-29.

From Glennon’s model [35], the basic nitrogen has to be

substituted by two hindered hydrophobic groups and a small

substituent. Thus, we continued to evaluate the importance

of the methyl group by replacing it with a more sterically

hindered group, such as ethyl or isopropyl. Compounds 19

and 20 were synthesized by two successive reductive amina-

tions (Scheme 5).

The second series was obtained in a similar manner as

compounds 21 and 22, by using reductive amination with the

piperazine derivative, thus furnishing expected com-

pounds 30 to 33 (Scheme 8).

Next, we studied the impact of a more rigid side chain by

preparing compounds 21 and 22. They were obtained from

reductive amination between the aldehyde 37 and indoline or

tetrahydroisoquinoline (Scheme 6).

3. RESULT AND DISCUSSION

All of the compounds were evaluated in binding assays

on human cerebral cortex ꢀ₁receptor using haloperidol as a

reference compound [37]. For compounds showing high ꢀ₁

affinity, binding assays were also performed on rat ꢀ₂recep-

tor [38]. The specific ligand binding to the receptors is de-

Finally, we introduced other constrained chains with

piperidine or piperazine as these moieties were frequently

observed in ꢀ₁ligands substructure (Schemes 7 and 8).

O

a

H

O

NH₂

N

R

N

+

N

43

R

O

10 R = CH₃

11 R =

14 R =

15 R =

17 R =

18 R =

OMe

F

12 R =

13 R =

Reagents. (a) NaBH(OAc)₃, CH₃COOH, THF, rt, overnight, 26%-56%.

Scheme (4). Syntehsis of compounds 10 - 18.

O

a

b

N

NH₂

N

R

N

H

N

43

48

O

19 R = ethyl

20 R = isopropyl

Reagents. (a) benzaldehyde, NaBH₄, TEA, EtOH, rt, overnight, 21% ; (b) NaBH(OAc)₃, AcOH, DCM, rt, overnight, 18-24%.

Scheme (5). Syntehsis of compounds 19 and 20.

O

n

O

n

HN

2

N

H

N

+

N

37

Reagents. (a) NaBH(OAc)₃%AcOH%DCM%rt%overnight%20-39%.

Scheme (6). Syntehsis of compounds 21 and 22.

21 n = 1

22 n = 2

O

New Synthesis of Tic-Hydantoins Sigma-1 Ligands and Pharmacological Evaluation

Medicinal Chemistry, 2010, Vol. 6, No. 6 359

O

b

N

a

OH

H

N

NBoc

N

NH

49

23

O

d

c

N

NH

N

R

50

O

NO₂

24 R =

25 R =

26 R =

27 R =

28 R =

29 R =

F

OMe

Reagents%(a) (i) Boc₂O, NaOH ) M, dioxane, H₂O, rt, overnight, 96%; (ii) HOBt, HBTU, DIEA, DCM, rt, overnight, 72%; (b) (i) TFA, DCM, rt, 3( min,

) ( ( %; (ii) CDI, DIEA, THF, 7( °C, overnight, 55%; (c) Pd/C, HCO₂NH₄, MeOH, reflux, 5h, 99%; (d) NaBH(OAc)₃, DCM, rt, overnight, 28%-94%%

Scheme (7). Syntehsis of compounds 24-29.

O

7

HN

R

N

R

N

H

+

N

37

O

OMe

F

32 R 4

33 R 4

30 R 4

31 R 4

ReagentA. %a( NaBH%OA8(_.) A8OH) THF) rt) =vernight) 5%-84%.

Scheme (8). Syntehsis of compounds 30-33.

fined as the difference between the total binding and the non-

specific binding determined in the presence of an excess of

unlabelled ligand. The biochemical results are presented as

the inhibition constant value Ki (Table 1) [39].

The replacement of the methyl by a similar group such as

ethyl, compound 19, has little effect while the replacement

by a hindered group isobutyl, 20 showed no activity. A

small, non-hindered substituent seems necessary for the

binding towards ꢀ₁. Moreover, the rigidification of the struc-

ture (compounds 21 and 22) did not influence the binding

affinity but decreased the selectivity.

In general, all the compounds were less potent than the

original hit and also less selective toward ꢀ₂protein. The

substitution of the aromatic ring was found to be unfavorable

(compounds 3, 4, 5 and 7). Especially when the ring was

substituted with a hydrophobic group, such as methyl or tert-

butyl (3 and 4), the binding affinity was completely lost.

Only nitro derivative 6 showed a mild affinity with a Ki of

19.5 nM. An electron withdrawing group appears to be fa-

forable for the binding. The introduction of a cyclohexyl 8

instead of the aromatic ring didn’t change the affinity but

decreased the selectivity between ꢀ₁and ꢀ₂.

In spite of the presence of piperidine and piperazine

moieties in several structures of ꢀ₁ligands, in this scaffold,

the introduction of this group led to lower activity (com-

pounds 23-33). Nitro group and cyclohexyl, usually better

substituents, were in this family unfavourable (compounds

27 and 29). On the other hand, for the piperazine family, the

addition of substituents increased the affinity. Nevertheless,

these compounds were less potent than compounds 1 and 2.

4. IN VIVO PHARMACOLOGY

The substitution of the basic nitrogen by two similar

aromatic rings (12-17) or aliphatic groups (9-11), hindered or

small substituents presented no activity toward ꢀ₁receptors

(data not shown, Ki >200nM). All of this data showed the

importance of only one hindered hydrophobic group in addi-

tion of the Tic-hydantoin on the nitrogen, which is consistent

with Glennon’s model.

In binding assays, compounds 19, 21 and 22 exhibited,

among the series of Tic-hydantoin derivatives, the most po-

tent affinity with a good selectivity. Thus, in a preliminary in

vivo experiment, these three compounds were examined on

the psychostimulant response induced by cocaine. These

effects were analysed by the measure of cocaine-induced

hyperlocomotion after acute injection of cocaine (10 mg/kg).

360 Medicinal Chemistry, 2010, Vol. 6, No. 6

Toussaint et al.

Table 1. Affinity of Tic-Hydantoin Compounds on ₁and ₂Receptors

Ki (nM)*

₁human

Ki (nM)*

₂human

Ratio

/

Ki (nM)*

₁human

Ki (nM)*

₁human

Compounds

2

1

2

7.2

10.4

88.7

118.0

102.6

19.5

44.4

12.9

12.3

> 200

10.6

12.3

557

823

nd

78

79

23

24

25

26

27

28

29

18.1

33.8

> 200

37.9

53.0

52.8

49.6

30

31

32

33

160.3

52.1

63.7

70.4

3

4

nd

5

nd

6

nd

7

nd

8

35

3

19

20

21

22

484

nd

39

467

489

44

34

The behavioural test was made following the protocol

described below. In brief, mice were separated into 4 groups.

Each mouse received a double intraperitoneal injection:

mice was highly significantly increased. Injection of com-

pound 19 (dotted columns) or 21 (hatched columns) failed to

affect the locomotor response in (V+V)- or (C+V)-treated

mice Fig. (3). In contrast, compound 22 (grey columns) sig-

nificantly increased the cocaine-induced effect without af-

fecting baseline locomotor activity (Fig. (3)). Thus effect of

compound 22 is coherent with an effective ꢀ₁agonist profile

[3, 19]. These experiments should be reproduced with enan-

tiomerically pure compounds and completed with locomotor

sensitization experiments.

1) Saline solution-saline solution (V/V)

2) Saline solution + cocaine (10 mg/kg) (V/C)

3) Saline solution-compound 19, 21 or 22 (1 mg/kg)

4) Cocaine (10 mg/kg) + compound 19, 21 or 22 (1 mg/kg)

The locomotor activity of each group of mice was meas-

ured by actimetry and results are shown in Fig. (3). After

acute injection of cocaine 10 mg/kg, locomotor acitivity of

5. CONCLUSION

ꢀ₁protein is known to modulate numerous neurotransme-

tors of the CNS and the identification of potent ligands is of

great interest for the treatment of drugs abuse such as co-

caine. Structure–activity relationship analysis was performed

on a class of Tic-hydantoin structure. The results suggest the

requirement of a basic nitrogen surrounded by two hydro-

phobic groups, which can tolerate hindrance and a smaller

substituent such as methyl or ethyl for the third substituent.

Moreover, the rigidification of the side chain appears to be

favorable for the binding with ꢀ₁. Three promising com-

pounds, 19, 21 and 22, show good affinities toward ꢀ ₁recep-

tors and compound 22 presents a potent and selective ꢀ₁

agonist profile, by potentiating the locomotor activity in-

duced by acute injection of cocaine. In parallel with this

study, a method for the separation of enantiomers of this Tic-

hydantoin family was developed [40] and will enable us to

get pure enantiomers of compounds. Efforts are currently

underway for further development of these classes of mole-

cules into more potent analogs with a convergent and non

racemising synthetic route and further studies will be con-

ducted in order to evaluate these three compounds on loco-

motor sensitization and appetitive properties induced by co-

caine.

Fig. (3). Effects of compounds 19, 21 and 22 on cocaine-induced

locomotor activity. Mice received saline or the compounds (1

mg/kg i.p.), 10 min before saline or cocaine 10 mg/kg, immediately

before placement in the activity cage. Lomcomotor activity was

recorded after 10 min and during 30 min. The number of animals

per group was 9-12. One-way ANOVA: F_(7,80)= 8.64, P < 0.0001.

** P < 0.01 vs. (V+V)-treated group; # P < 0.05 vs. (C+V)-treated

group; Dunnett's test.

New Synthesis of Tic-Hydantoins Sigma-1 Ligands and Pharmacological Evaluation

Medicinal Chemistry, 2010, Vol. 6, No. 6 361

6. MATERIALS AND METHODS

6.1. Chemistry

the solution was heated at 70°C for 2 h. After evaporation,

the residue was dissolved in CH₂Cl₂(50 mL). The organic

layer was washed with an aqueous solution of NaHCO₃(5

%, 1 x 30 ml) and then dried over MgSO₄. The solvent was

evaporated and the residue was purified by TLC

(CH₂Cl₂/MeOH : 95/5) to yield expected compound 35 as a

white solid (537 mg, 70 % yield). TLC (CH₂Cl₂/MeOH :

9/1) Rf = 0.7; HPLC (TSK gel, 10 min): tr = 4.1 min ; P_HPLC

All reactions were monitored by thin-layer chromatogra-

phy carried out on 0.2 mm E. Merck silica gel plates (60F-

254) using UV light as a visualizing agent. Chromatography

was undertaken using silica gel 60 (230–400 mesh ASTM)

from Macherey-Nagel. Thin layer chromatography (TLC)

was performed using silica gel from Merck, from which the

compounds were extracted by the following solvent system:

CH₂Cl₂/MeOH/NH₄OH, 80:20:1. NMR spectra were ob-

tained using a Bruker 300 MHz spectrometer, chemical shifts

(d) were expressed in ppm relative to TMS used as an inter-

nal standard.

1

= 95 %; MALDI-TOF: 203,05 [M+H]⁺; H NMR 300 MHz

2

(DMSO), (ppm) : 2.85 (dd, 1H, H_10ꢀ, J = 15Hz, J_10ꢀ-10a

=

2

12Hz); 3.11 (dd, 1H, H_10ꢁ, J = 15Hz, J_10ꢁ-10a= 5Hz); 4.19

(dd, 1H, H_10a, J_10a-10ꢀ= 12Hz, J_10a-10ꢁ= 5Hz) ; 4.31 (d, 1H,

H₅, ²J = 17Hz) ; 4.78 (d, 1H, H₅, ²J = 17Hz) ; 7.2-7.3 (m, 4H,

H

_aro), 10.93 (s, 1H, NH); ¹³C NMR 75 MHz (CDCl₃), (ppm):

30.3 (C₁₀) ; 41.6 (C₅) ; 56.1 (C_10a); 127.9-129.9 (C_aro).

The attributions of the carbons are deduced after 2D ex-

periments have been performed. Mass spectra were recorded

on a MALDI-TOF Voyager-DE STR (Applied Biosystems,

Palo Alto CA) with a trihydroxyacetophenone matrix. The

purity of final compounds was verified by two types of high

pressure liquid chromatography (HPLC) columns: C18 Del-

tapak (C18N) and C4 Interchrom UP5WC4-25QS (C4).

Analytical HPLC was performed on a Shimadzu system

equipped with a UV detector set at 254 nm. Compounds

were dissolved in Tampon B or MeOH and injected through

a 50 mL loop.

2-(2-[1,3]dioxolan-2-yl-ethyl)-10,10a-dihydro-5H-imidazo

[1,5-b]isoquinoline-1,3-dione 36

To a solution of 35 (0.74 mmol, 150 mg) in DMF (15

mL) was added potassium carbonate (1 eq, 102 mg). After

stirring for 20 min, bromoethyldioxolane (1.1 eq, 0.095 mL)

was added and the mixture was heated at 70°C overnight.

The solvent was evaporated and the residue was purified by

TLC (cyclohexane/EtOAc : 3/7) to yield expected compound

36 as a white solid (156 mg, 70 % yield).

TLC (Cyclohexane/AcOEt : 3/7) Rf = 0.6, HPLC (TSK

gel, 10 min) : tr = 4.8 min ; PHPLC = 92 %, MALDI-TOF :

303,1 [M+H]+ ; 1H NMR 300 MHz (CDCl3), ꢂ(ppm) : 2.0-

2.1 (m, 2H, H2); 3.24 (dd, 1H, H10ꢀ, J10ꢀ-10a = 16Hz, 2J =

12Hz) ; 3.72 (dd, 1H, H10ꢁ, J10ꢁ-10a = 5Hz, 2J = 12Hz) ;

3.6-3.7 (m, 2H, H1) ; 3.8-3.9 (m, 4H, H3 et H4) ; 4.06 (dd,

1H, H10a, J10ꢀ-10a = 12H, J10ꢁ-10a = 5Hz) ; 4.42 (d, 1H,

H5, 2J = 16Hz) ; 4.95 (t, 1H, H6, J6-2 = 4Hz) ; 5.02 (d, 1H,

H5, 2J = 16Hz) 7.2-7.3 (m, 4H, Haro); 13C NMR 75 MHz

(CDCl3), ꢂ(ppm) : 30.7 (C10) ; 31.7 (C2) ; 34.1 (C1) ; 41.7

(C5) ; 54.7 (C10a) ; 64.9 (C3 et C4) ; 102.8 (C6) ; 126.7-

127.2-127.4-129.5 (Caro).

The following eluent systems were used: Tampon A

(H₂O/TFA, 100:0.05) and Tampon B (CH₃CN/H₂O/TFA,

80:20:0.05). HPLC retention times (HPLC tR) were ob-

tained, at a flow rate of 1 mL/min, using the following condi-

tions: for the 10 min method: a gradient run from 100 % elu-

ent A during 30 s, then to 100 % eluent B over the next 8

min and for the 40 min method: a gradient run from 100 %

eluent A during 1 min, then to 100 % eluent B over the next

30 min. Chiral chromatography was carried out on a Chiral-

pak AD (tris-2,5-dimethylphenylcarbamate, 250 ± 4.6 mm

I.D.; 10 mm; Daicel Chemical Industries, Baker, France)

using a gradient Waters 600E metering pump model

equipped with a Waters 996 photodiode array spectropho-

tometer (Waters, St Quentin-en-Yvelines, France). Chroma-

tographic data were collected and processed on a computer

running Millennium 2010. The sample loop was 20 mL

(Rheodyne 7125 injector). The column eluate was monitored

at 206 nm and 266 nm. For hydantoı¨ns 2 and 5, chiral sepa-

ration was performed at 40°C using an isocratic mobile

phase of n-hexane/ethanol (40:60, v/v) at a flow rate of 1

mL/min. For thiohydantoïn 8, chiral separation was per-

formed at 20°C using an isocratic mobile phase of n-

hexane/2-propanol (90:10, v/v) at a flow rate of 1 mL/min.

The peak of the solvent front was considered to be equal to

the dead time (t0) and was about 4.50 min. Compounds were

chromatographed by dissolving them in ethanol to a concen-

tration of 0.5 mM and passed through a 0.45 mm membrane

filter prior to loading the column. Reagents were obtained

from Acros, Aldrich, Lancaster, Novabiochem and Avocado.

3-(1,3-dioxo-1,5,10,10a-tetrahydroimidazo[1,5-b]isoquino-

line-2-yl)-propionaldehyde 37

A solution of 36 (1.09 mmol, 329 mg) in acetone / HCl

37 % (36 / 4 mL) was stirred for 1 h at r.t.. The solvent was

evaporated and the crude dissolved in CH₂Cl₂(40 mL). The

organic layer was then washed with a saturated solution of

NaHCO₃(2 x 20mL) and dried over MgSO₄. The aldehyde

37 was used without purification in the next step. H-

1

PLC (TSK gel, 10 min) : tr = 3.9 min ; P_HPLC= 99 %, H

NMR 300 MHz (CDCl₃), ꢂ(ppm) : 2.0-2.1 (m, 2H, H₂) ; 2.85

2

(dd, 1H, H_10ꢀ, J_{10ꢀ 10a}

-

= 16Hz, J = 12Hz) ; 3.27 (dd, 1H,

2

H_10ꢁ, J_10ꢁ-10a= 5Hz, J = 12Hz) ; 3.9-4.0 (m, 2H, H₁) ; 4.08

(dd, 1H, H_10a, J_10ꢀ-10a= 12H, J_10ꢁ-10a= 5Hz) ; 4.42 (d, 1H, H₅,

²J = 16Hz) ; 5.02 (t, 1H, H₆, J_6-2= 4Hz) ; 5.02 (d, 1H, H₅, ²J

= 16Hz); 7.2-7.3 (m, 4H, H_aro); 9.80 (t, 1H, H₃, J₃-₂= 1,2Hz).

2-{3-[(4-fluorobenzyl)methylamino]propyl}-10,10a-dihydro-

5H-imidazo[1,5-b]isoquinoline-1,3-dione 7

10,10a-dihydro-5H-imidazo[1,5-b]isoquinoline-1,3-dione 35

To a suspension of TicOH (3.8 mmol, 668 mg) in DMF

(60 mL), was added potassium isocyanate (2 eq, 612 mg).

The mixture was then heated at 70°C for 2 h. An aqueous

solution of HCl (35 %) was added dropwise until pH = 1 and

To a solution of fluorobenzylamine (2.4 mmol, 300 mg)

in CH₂Cl₂(10 mL) was added a solution of Boc₂O (1.1 eq,

575 mg) in CH₂Cl₂(5 mL) at 0°C and the reaction was

stirred overnight at r.t. The organic layer was washed with an

362 Medicinal Chemistry, 2010, Vol. 6, No. 6

Toussaint et al.

aqueous solution of citric acid (5 %, 2 x 5 mL), a saturated

solution of NaCl (1 x 5 mL) and dried over MgSO₄. the sol-

vent was evaporated to give tert-butyl N-(4-fluorobenzyl)-

carbamate as a white solid (465 mg, 86 % yield). TLC

(AcOEt/Cyclohexane : 3 / 7) Rf = 0.4 ; HPLC (TSK gel, 10

2-[3-(N-cyclohexyl-N-methylaminopropyl]-10,10a-dihydro-

5H-imidazo[1,5-b]isoquinoline-1,3-dione 8

To a solution of cyclohexylamine (3 mmol, 339 mg) in

CH₂Cl₂(10 mL) was added a solution of Boc₂O (1.1 eq, 720

mg) in CH₂Cl₂(5 mL) at 0°C and the reaction was stirred

overnight at r.t. The organic layer was washed with an aque-

ous solution of citric acid (5 %, 2 x 5 mL) a saturated solu-

tion of NaCl (1 x 5 mL) and dried over MgSO₄. The solvent

was evaporated to give tert-butyl N-cyclohexylmethyl-

carbamate as an oil (639 mg, 100 % yield). TLC (AcO-

1

min) : tr = 6.3min ; P_HPLC= 91 %; H NMR 300 MHz

(CDCl₃), ꢀ(ppm): 1.46 (s, 9H, C(CH₃)₃); 4.27 (d, 2H, H₇, J_7-

= 6Hz) ; 4.8-4.9 (m, 1H, NH); 6.9-7.0 (m, 2H, H₃et H₅,

NH

J

_5-6= J_5-F= J_3-2= J_3-F= 8.7Hz, J_5-3= 3Hz); 7.2-7.3 (m, 2H, H₆

et H₂); ¹³C NMR 75 MHz (CDCl₃), ꢀ(ppm) : 28.4 (C(CH₃)₃);

43.9 (C₇) ; 115.3 (C₃et C₅, J_C-F= 21.4Hz) ; 129.1 (C₂et C₆,

J_C-F= 7.5Hz).

1

Et/MeOH : 96/4) Rf = 0.9; H NMR 300 MHz (CDCl₃),

ꢀ(ppm) : 0.9-1.0 (m, 2H, H_2a); 1.2-1.3 (m, 3H, H_3aet H_4a) ;

1.3-1.4 (m, 10H, C(CH₃)₃et H_1a) ; 1.6-1.8 (m, 5H, H_4e, H_2eet

H_3e) ; 2.95 (t, 2H, H₅, J_5-1a= 6.3Hz) ; 4.56 (s, 1H, NH); ¹³C

NMR 75 MHz (CDCl₃), ꢀ(ppm) : 25.9 (C₃) ; 26.4 (C₄) ; 28.5

(C(CH₃)₃) ; 30.7 (C₂) ; 38.4 (C₁) 46.9 (C₅).

To a solution of tert-butyl-N-(4-fluorobenzyl)-carbamate

(1.99 mmol, 450 mg) in anhydrous DMF (10 mL) was added

NaH (60 % w/w, 4 eq, 320 mg) at 0°C. The reaction was

stirred for 1 h at r.t. Then, MeI (4 eq, 0.697 mL) was added

and the mixture was stirred overnight at r.t.. The reaction

was quenched with water (20 mL). The aqueous layer was

extracted with EtOAc (4 x 40mL). The organic layers were

combined and dried over MgSO₄. After evaporation, the

residue was purified by TLC (cyclohexane/EtOAc : 8/2) to

yield tert-butyl N-(4-fluorobenzyl)-N-methylcarbamate as an

oil (266 mg, 56 % yield). TLC (AcOEt/Cyclohexane : 2/8)

To a solution of tert-butyl-N-cyclohexylmethylcarbamate

(3 mmol, 639 mg) in anhydrous DMF (20 mL) was added

NaH (60 % w/w, 4 eq, 482 mg) at 0°C. The reaction was

stirred for 1 h at r.t. Then, MeI (4 eq, 0.60 mL) was added

and the mixture was stirred overnight at r.t.. The reaction

was quenched with water (20 mL) and the aqueous layer

extracted with EtOAc (4 x 40mL). The organic layers were

combined and dried over MgSO₄. After evaporation, the

residue was purified by TLC (cyclohexane/EtOAc : 6/4) to

yield tert-butyl-N-cyclohexylmethyl-N-methylcarbamate as

an oil (157 mg, 23 % yield). TLC (AcOEt/Cyclohexane :

Rf = 0.6 ; HPLC (TSK gel, 10 min) : tr = 7.1 min ; P_HPLC

=

1

85 %; H NMR 300 MHz (CDCl₃), ꢀ(ppm) : 1.46 (s, 9H,

C(CH₃)₃); 2.80 (s, 3H, H₈) ; 4.38 (s, 2H, H₇); 6.9-7.1 (m, 2H,

H₅et H₃, J_5-6= J_5-F= J_3-2= J_3-F= 8,7Hz, J_5-3= 3Hz) ; 7.2-7.3

(m, 2H, H₂et H₆, J_6-5= J_2-3= 8,7Hz, J_6-F= J_2-F= 5.7Hz); ¹³C

NMR 75 MHz (CDCl₃), ꢀ(ppm): 28.3 (C(CH₃)₃) ; 33.7 (C₈);

51.9 (C₇) ; 115.3 (C₃et C₅, J_C-F= 21.3Hz) ; 128.9 (C₂et C₆).

1

15/85) Rf = 0.6 ; H NMR 300 MHz (CDCl₃), ꢀ(ppm) : 0.8-

0.9 (m, 2H, H_2a); 1.1-1.2 (m, 3H, H_3aet H_4a) ; 1.45 (s, 9H,

C(CH₃)₃) ; 1.6-1.7 (m, 6H, H_4e, H_2e, H_1a, H_3e) ; 2.83 (s, 3H,

H₆) ; 3.0-3.1 (m, 1H, H₅); 4.56 (s, 1H, NH). ¹³C NMR 75

MHz (CDCl₃), ꢀ(ppm) : 25.8 (C₃) ; 26.4 (C₄) ; 28.4

(C(CH₃)₃) ; 30.6 (C₂) ; 35.0 (C₆); 37.0 (C₁); 55.5 (C₅).

A

solution of tert-butyl N-(4-fluorobenzyl)-N-

methylcarbamate (1.1 eq, 0.56 mmol) in CH₂Cl₂/TFA

(1.5/1.5 mL) was stirred for 30 min at r.t., evaporated to dry-

ness to yield compound 38. The residue was solubilised in

CH₂Cl₂(15 mL), aldehyde 37 (0.51 mmol, 71 mg) was

added and the mixture was stirred for 15 min at r.t..

NaBH(OAc)₃(5 eq, 540 mg) and glacial acetic acid (2 eq,

0,01 mL) were added and the solution was stirred overnight

at r.t.. The reaction was quenched with an aqueous solution

of NaHCO₃(30mL) followed by extraction with CH₂Cl₂

(3x30mL). The organic layers were combined and dried over

MgSO₄. The solvent was evaporated and the residue was

purified by TLC (CH₂Cl₂/MeOH : 95/5) to yield expected

compound 7 as a yellow oil (87 mg, 41 % yield). TLC

(CH₂Cl₂/MeOH : 95/5) Rf = 0.6; HPLC (TSK gel, 10 min) :

tr = 4.5 min; P_HPLC=98 %; HPLC (C4, 40 min) : tr = 21.9

A

solution

of

tert-butyl-N-cyclohexylmethyl-N-

methylcarbamate (0.99 mmol) in CH₂Cl₂/TFA (3/3 mL) was

stirred for 30 min at r.t., evaporated to dryness. The residue

was solubilised in ethyl acetate (30mL), washed with NaOH

1M (30 mL). Aqueous layer was washed with ethyl acetate

(2 x 30mL). The organic layers were combined and dried

over MgSO₄, evaporated to yield compound 39, which was

solubilised in CH₂Cl₂(20 mL). Aldehyde 37 (1.1 eq, 1.09

mmol) in CH₂Cl₂(20 mL) was added and the mixture was

stirred for 15 min at r.t.. NaBH(OAc)₃(5 eq, 1.45 g) and

glacial acetic acid (2 eq, 0.057 mL) were added and the solu-

tion left stirred overnight at r.t.. The reaction was quenched

with an aqueous solution of NaHCO₃(30mL) followed by

extraction with CH₂Cl₂(3x30mL). The organic layers were

combined and dried over MgSO₄. The solvent was evapo-

rated and the residue was purified by TLC (CH₂Cl₂/MeOH :

95/5) to yield expected compound 8 as a white solid (149

mg, 37 % yield). TLC (CH₂Cl₂/MeOH : 95/5) Rf =0.4;

HPLC (TSK gel, 10 min) : tr = 4.9 min ; P_HPLC= 97 %;

HPLC (TSK gel, 10 min) : tr = 19.4 min ; P_HPLC= 91 %;

1

min ; P_HPLC= 98 %; MALDI-TOF: 382.3 [M+H]⁺; H NMR

300 MHz (CDCl₃), ꢀ(ppm) : 1.86 (quint, 2H, H_2’, J_2’-1’= J_2’-3’

= 7Hz); 2.16 (s, 3H, H_4’); 2.42 (t, 2H, H_3’, J_3’-2’= 7Hz); 2.76

(dd, 1H, H_10ꢁ, ²J = 15Hz, J_10ꢁ-10a= 12Hz); 3.24 (dd, 1H, H_10ꢂ

,

²J = 15Hz, J_10ꢂ-10a= 5Hz); 3.43 (s, 2H, H_5’); 3.6-3.7 (m, 2H,

H_1’); 4.05 (dd, 1H, H_10a, J_10a-10ꢁ= 12Hz, J_10a-10ꢂ= 5Hz); 4.41

2

1

MALDI-TOF : 370.2 [M+H]⁺; H NMR 300 MHz (CDCl₃),

(d, 1H, H₅, J = 17Hz); 5.02 (d, 1H, H₅, J = 17Hz); 6.9-7.0

(m, 2H, H_7’,H_8’, J_7’-6’= J_7’-F= J_8’-9’= J_8’-F= 8,7Hz, J_7’-8’

=

ꢀ(ppm) : 0.8-0.9 (m, 2H, H_7’a); 1.1-1.2 (m, 3H, H_8’aet H_9’a);

1.4-1.5 (m, 1H, H_6’a); 1.7-1.9 (m, 7H, H_7’e, H_8’e,H_9’eet H_2’) ;

2.7Hz) ; 7.1-7.3 (m, 6H, H_6’, H_9’, H₆, H₇, H₈et H₉); ¹³C

NMR 75 MHz (CDCl₃), ꢀ(ppm) : 25.8 (C_2’); 30.8 (C₁₀); 37.1

(C_1’); 41.6 (C₅); 41.8 (C_4’); 54.5 (C_10a); 54.6 (C_3’); 61.5 (C_5’);

114.7-115.0 (C_7’et C_8’, J_C-F= 21Hz); 126.6-130.5 (C_6’, C_9’,

C₆, C₇, C₈et C₉).

2.10 (d, 2H, H_5’, J_5’-6’= 7Hz) ; 2.19 (s, 3H, H_4’) ; 2.38 (t, 2H,

2

H_3’, J_3’-2’= 7Hz) ; 2.84 (dd, 1H, H_10ꢁ, J = 16Hz, J_10ꢁ-10a

=

12Hz); 3.27 (dd, 1H, H_10ꢂ, ²J =16Hz, J_10ꢂ-10a= 5Hz); 3.61 (t,

2H, H_1’, J_1’-2’= 7Hz); 4.08 (dd, 1H, H_10a, J_10a-10ꢁ= 12Hz_,J_10a-

New Synthesis of Tic-Hydantoins Sigma-1 Ligands and Pharmacological Evaluation

Medicinal Chemistry, 2010, Vol. 6, No. 6 363

2

_10ꢀ= 5Hz); 4.42 (d, 1H, H₅, ²J = 17Hz) ; 5.02 (d, 1H, H₅, ²J =

17Hz) ; 7.2-7.3 (m, 4H, H_aro); ¹³C NMR 75 MHz (CDCl₃),

ꢁ(ppm) : 25.7 et 26.0 (C_8’et C_9’) ; 30.8 (C₁₀) ; 31.7 (C_7’) ;

35.6 (C_6’) ; 37.2 (C_1’) ; 41.5 (C₅) 42,5 (C_4’) ; 54.6 (C_10a) ;

55.5 (C_3’) 64.7 (C_5’) ; 125.3-129.4 (C_aro).

2H, H_2’, J_2’-3’= J_2’-1’= 7Hz) ; 2.67 (dd, 1H, H_4ꢂ, J = 16Hz,

J_4ꢂ-3= 5Hz) ; 3.04 (q, 2H, H_3’,J_3’-2’= 6Hz) ; 3.11 (dd, 1H,

H_4ꢀ,²J = 16Hz, J_4ꢀ-3= 10Hz) ; 3.26 (q, 2H, H_1’, J_1’-2’

=

6Hz) ; 3.49 (dd, 1H, H₃, J_3-4ꢀ= 10Hz, J_3-4ꢂ= 5Hz) ; 3.94 (m,

2H, H₁); 4.99 (t, 1H, NHBoc) ; 6.97 (m, 1H, H_5’’) ; 7.0-7.1

(m, 3H, H_2’’, H_3’’et H_4’’) ; 7.38 (t, 1H, NHCO); ¹³C NMR 75

MHz (CDCl₃), ꢁ(ppm) : 28.6 (C(CH₃)₃) ; 30.3 (C_2’) ; 31.3

(C₄) ; 36.0 (C_1’) ; 37.4 (C_3’) ; 47.6 (C₁) ; 56.6 (C₃) ; 125.8

(C_5’’); 126.0-126.4-126.8-129.3 (C_2’’, C_3’’et C_4’’).

10,10a-dihydro-5H-oxazolo[3,4-b]isoquinoline-1,3-dione 40

To a solution of TicOH (2.82 mmol, 500 mg) in 1,4-

dioxane / H₂O / NaOH 1M (5 / 5 / 5 mL) was added a solu-

tion of Boc₂O (1.1 eq, 677 g) in 1,4-dioxane (5mL). The so-

lution was then stirred at r.t. overnight. The solvent was

evaporated and the crude dissolved in EtOAc. The organic

phase was washed with an aqueous solution of citric acid (5

%, 2x20 mL), brine (20 mL) and dried over MgSO₄. The

solvent was evaporated to yield Boc-L-Tic-OH as a white

solid (751 mg, 96 %). TLC (CH₂Cl₂/MeOH : 9/1) Rf = 0.7 ;

2-(3-aminopropyl)-10,10a-dihydro-5H-imidazo[1,5-b]isoqui-

noline-1,3-dione 43

To a solution of 42 (0.37 mmol, 124 mg) in THF (10 mL)

was added DIEA (5 eq, 0,3 mL) and the mixture was stirred

for 10 min at r.t. Then CDI was added (3 eq, 181 mg) and the

solution was heated at 70°C overnight. The solvent was

evaporated and the residue was dissolved in EtOAc (20 mL).

The organic layer was washed with an aqueous solution of

NaHCO₃(5 %, 10 ml) and a saturated solution of NaCl (10

mL) and then dried over MgSO₄. The solvent was evapo-

rated and the residue was purified by TLC (CH₂Cl₂/MeOH :

95/5) to tert-butyl N-[3-(1,3-dioxo-1,5,10,10a-tetrahydroimi-

dazo[1,5-b]isoquinoline-2-yl)propyl]carbamate as a white

solid (102 mg, 77 % yield). TLC (CH₂Cl₂/MeOH : 9/1) Rf =

0.8; HPLC (TSK gel,10 min) : tr = 5.9 min ; P_HPLC= 77 %;

1

HPLC (TSK gel, 10 min) : tr = 5.7min ; P_HPLC= 99 %; H

NMR 300MHz (CDCl₃), ꢁ(ppm) : 1.34 (s, 9H, C(CH₃)₃) ;

3.0-3.1 (m, 2H, H₁₀) ; 4.3-4.4 (m, 1H, H₅) ; 4.5-4.6 (m, 1H,

H_10a) ; 4.6-4.7 (m, 1H, H₅) ; 7.0-7.2 (m, 4H, H_aro); ¹³C NMR

75MHz (CDCl₃), ꢁ(ppm) : 28.2 (C(CH₃)₃) ; 30.8 (C₁₀) ; 44.5

(C₅) ; 54.1 (C_10a); 126.2-126.8-127.8-128.5 (C_aro).

To a solution of Boc-TicOH (3.6 mmol, 500 mg) in

CH₂Cl₂(7 mL) was added PCl₃(1.3 eq, 0.41 mL) at 0°C. The

solution was then allowed to warm at r.t. and stirred for 2 h.

The solvent was evaporated and the solid filtered and washed

with hexane to yield expected compound 40 as a white solid

(731 mg, 100 % yield). TLC (CH₂Cl₂/MeOH : 95/5) Rf =

MALDI-TOF : 360.2 [M+H]⁺; H NMR 300 MHz (CDCl₃),

1

ꢁ(ppm) : 1.37 (s, 9H, C(CH₃)₃) ; 1.75 (quint, 2H, H_2’,J_2’-1’

=

J_2’-3’= 6Hz) ; 2.77 (dd, 1H, H_10ꢂ,²J = 15Hz, J_10ꢂ-10a= 11Hz) ;

3.06 (q, 2H, H_1’, J_1’-2’= 6Hz) ; 3.21 (dd, 1H, H_10ꢀ,²J = 15Hz,

J_10ꢀ-10a= 5Hz) ; 3.58 (t, 2H, H_3’, J_3’-2’= 6Hz) ; 4.04 (dd, 1H,

1

0.7; H NMR 300 MHz (CDCl₃), ꢁ(ppm) : 3.1-3.2 (m, 2H,

H₁₀) ; 4.46 (d, 1H, H₅, ²J = 16Hz) ; 4.62 (dd, 1H, H_10a, J_10a-10ꢂ

= 11Hz_,J_10a-10ꢀ= 5Hz) ; 4.78 (d, 1H, H₅, ²J = 16Hz) ; 7.2-7.3

(m, 4H, H_aro); ¹³C NMR 75 MHz (CDCl₃), ꢁ(ppm) : 31.8

(C₁₀); 45.3 (C₅); 57.1 (C_10a); 130.0-130.4-131.0-132.3 (C_aro).

2

H_10a,J_10a-10ꢂ= 11Hz, J_10a-10ꢀ= 5Hz) ; 4.36 (d, 1H, H₅, J =

2

17Hz) ; 4.96 (d, 1H, H₅, J = 17Hz) ; 5.09 (t, 1H, NH); 7.1-

7.2 (m, 4H, H_aro); ¹³C NMR 75 MHz (CDCl₃), ꢁ(ppm) : 28.6

(C(CH₃)₃) ; 29.1 (C_2’) ; 31.1 (C₁₀) ; 36.0 (C_3’) ; 37.3 (C_1’) ;

41.8 (C₅) ; 54.9 (C_10a) ; 126.7-127.3-127.4-129.5 (C_aro).

N-Boc-1,3-diaminopropane 41

A

solution of tert-butyl-N-[3-(1,3-dioxo-1,5,10,10a-

To a solution of 1,3-aminopropane (7 eq, 12.0 mL) in

CHCl₃(200 mL), was added dropwise a solution of Boc₂O

(20.3 mmol, 4.37 g) in CHCl₃(100mL) at 0°C over a period

of 4 h.Then, the solution was stirred at r.t. overnight. The

mixture was washed with brine (4 x 100 ml) and water (1 x

100 mL) and then dried over MgSO₄. The solvent was

evaporated to yield expected compound 41 as a white oil

(3.32 g, 94 % yield). TLC (CH₂Cl₂/MeOH : 8/2) Rf = 0.4;

¹H NMR 300 MHz (CDCl₃), ꢁ(ppm) : 1.38 (s, 9H, C(CH₃)₃) ;

1.55 (quint, 2H, H₂, J_2-1= J_2-3= 6,6Hz) ; 2.70 (t, 2H, H₃, J_3-2

= 6,6Hz) ; 3.14 (q, 2H, H₁, J_1-2= 6,5Hz) ; 4.85 (s, 1H, NH);

¹³C NMR 75 MHz (CDCl₃), ꢁ(ppm) : 28.6 (C(CH₃)₃) ; 33.6

(C₂) ; 38.6 (C₁) ; 39.9 (C₃).

tetrahydroimidazo[1,5-b]isoquinoline-2-yl)propyl]carbamate

(5.17mmol, 1.86g) in CH₂Cl₂/TFA (15/15 mL) was stirred

for 30 min. The solvent was evaporated. CH₂Cl₂(50 mL)

was added and the organic layer was washed with an aque-

ous solution of NaOH (1M, 20 mL). The aqueous layer was

extracted with CH₂Cl₂(3 x 50 mL). The organic layers were

combined and dried over MgSO₄. The solvent was evapo-

rated to yield expected compound 43 as an oil (1 g, 75 %

yield). TLC (CH₂Cl₂/ MeOH : 95 / 5) Rf = 0.1; HPLC (TSK

gel,10 min) : tr = 3.94 min ; P_HPLC= 99 %; MALDI-TOF :

260.2 [M+H]⁺; H NMR 300 MHz (CDCl₃), ꢁ(ppm) : 2.01

1

(quint, 2H, H_2’,J_2’-1’= J_2’-3’= 7Hz) ; 2.93 (dd, 1H, H_10ꢂ,²J =

15Hz, J_10ꢂ-10a= 12Hz) ; 3.02 (t, 2H, H_1’, J_1’-2’= 7Hz) ; 3.27

(dd, 1H, H_10ꢀ,²J = 15Hz, J_10ꢀ-10a= 5Hz) ; 3.69 (t, 2H, H_3’, J_3’-

_2’= 7Hz) ; 4.29 (dd, 1H, H_10a,J_10a-10ꢂ= 12Hz, J_10a-10ꢀ= 5Hz) ;

tert-butyl N-{3-[(1,2,3,4-tetrahydroisoquinoline-3-carbom-

oyl)amino]propyl}carbamate 42

2

4.48 (d, 1H, H₅, J = 17Hz) ; 4.96 (d, 1H, H₅, J = 17Hz) ;

4.99 (t, 1H, NH); 7.2-7.3 (m, 4H, H_aro); ¹³C NMR 75 MHz

(CDCl₃), ꢁ(ppm) : 26.5 (C_2’) ; 30.4 (C₁₀) ; 35.3 (C_3’) ; 37.3

(C_1’); 41.6 (C₅); 55.3 (C_10a); 126.7-127.2-127.3-129.5 (C_aro).

To a solution of the diamine 41 (1.3 eq, 268 mg) in an-

hydrous CH₂Cl₂(12 mL) was added 40 (1.2 mmol, 240 mg)

and DIEA (2 eq, 0.4 mL). The mixture was stirred at r.t.

overnight. After evaporation, the residue was purified by

TLC (CH₂Cl₂/MeOH : 9/1) to yield expected compound 42

as a white solid (243 mg, 61 % yield). TLC (AcOEt/EtOH :

9/1) Rf = 0.3 ; HPLC (TSK gel, 10 min) : tr = 4.1 min ;

2-(3-methylaminopropyl)-10,10a-dihydro-5H-imidazo[1,5-

b]isoquinoline-1,3-dione 44

1

P_HPLC= 90 % ; MALDI-TOF : 334.3 [M+H]⁺; H NMR 300

To a solution of amine 43 (0.5 mmol, 129 mg) in MeOH

(5 mL) was added formaldehyde (37 %, 1 eq, 0.04 mL) and

the mixture was stirred for 10 min at r.t.. Then, formic acid

MHz (CDCl₃), ꢁ(ppm) : 1.36 (s, 9H, C(CH₃)₃) ; 1.57 (quint,

364 Medicinal Chemistry, 2010, Vol. 6, No. 6

Toussaint et al.

(2 eq, 0.04mL) was added and the solution was stirred over-

night at r.t.. The solvent was evaporated and the residue was

purified by TLC (CH₂Cl₂/MeOH : 85/15) to yield expected

compound 44 as an oil (35 mg, 26 % yield). TLC

(CH₂Cl₂/MeOH : 9/1) Rf = 0.2; HPLC (TSK gel, 10 min) : tr

55.1 (OCH₃) ; 61.5 (C_5’); 126.5-127.2 (C_7’) 129.3-130.1 (C_6’,

C₆, C₇, C₈et C₉).

2-[3-(4-methylbenzylamino)propyl]-10,10a-dihydro-5H-imid-

azo[1,5-b]isoquinoline-1,3-dione 45

1

= 3.6 min ; P_HPLC= 87 %. MALDI-TOF : 274.1 [M+H]⁺; H

To a stirred solution of 42 (0.38 mmol, 135 mg) in

MeOH (5 mL) was added an aqueous solution of HCl (12N,

3 eq, 0.095mL) and the mixture was stirred for 2.5 h at r.t..

The solvent was evaporated and the crude was diluted in

EtOH (5 mL). p-Tolualdehyde (1.1 eq, 0.049mL), TEA, (4

eq, 0.211mL) and molecular sieves 3Å were added. The so-

lution was stirred for 3 h and then cooled at 0°C. NaBH₄(5

eq, 71 mg) was added portionwise and the mixture was al-

lowed to warm at r.t. and stirred overnight. Water (10 mL)

was added and the solution was filtered throught celite. The

solvent was evaporated. NaOH (1M, 10 mL) was added to

the crude. The aqueous layer was extracted with CH₂Cl₂(3 x

20 mL). The organic layers were combined and dried over

MgSO₄. The solvent was evaporated and the residue was

purified by TLC (CH₂Cl₂/MeOH : 95/5) to yield expected

compound 45 as an oil (91 mg, 66 % yield). TLC

(CH₂Cl₂/MeOH : 95/5) Rf = 0.5; HPLC (TSK gel, 10 min) :

tr = 4.8min; P_HPLC= 90 %; MALDI-TOF : 364.1 [M+H]⁺; ¹H

NMR 300 MHz (CDCl₃), ꢀ(ppm) : 1.89 (quint, 2H, H_2’, J_2’-1’

NMR 300 MHz (CDCl₃), ꢀ(ppm) : 1.85 (quint, 2H, H_2’,J_2’-1’

= J_2’-3’= 7Hz) ; 2.43 (s, 3H, H_4’) ; 2.61 (t, 2H, H_3’,J_3’-2’

=

7Hz) ; 2.84 (dd, 1H, H_10ꢁ,²J = 15Hz, J_10ꢁ-10a= 12Hz) ; 3.24

(dd, 1H, H_10ꢂ,²J = 15Hz, J_10ꢂ-10a= 5Hz) ; 3.66 (t, 2H, H_1’, J_1’-

_2’= 7Hz) ; 4.11 (dd, 1H, H_10a,J_10a-10ꢁ= 12Hz, J_10a-10ꢂ= 5Hz) ;

2

4.39 (d, 1H, H₅, J = 17Hz) ; 4.96 (d, 1H, H₅, J = 17Hz) ;

7.1-7.3 (m, 4H, H_aro); ¹³C NMR 75 MHz (CDCl₃), ꢀ(ppm) :

27.3 (C_2’) ; 30.6 (C₁₀) ; 35.6 (C_1’); 36.9 (C_3’) ; 41.6 (C₅); 50.2

(C_4’); 54.7 (C_10a) ; 126.6-127.2-127.3-129.4 (C_aro).

2-(3-dimethylaminopropyl)-10,10a-dihydro-5H-imidazo[1,5-

b]isoquinoline-1,3-dione 9

This tertiary amine was obtained as a by-product in the

previous experiment and was isolated as an oil (10 mg, yield

7 %). TLC (CH₂Cl₂/MeOH : 98/2) Rf = 0.5; HPLC (TSK

gel, 10 min) : tr = 4.1min ; P_HPLC= 99 %; HPLC (C4, 40

min) : tr = 9.2 min ; P_HPLC= 99 %; MALDI-TOF : 288.2

1

[M+H]⁺; H NMR 300 MHz (CDCl₃), ꢀ(ppm) : 1.82 (quint,

= J_2’-3’= 7Hz); 2.32 (s, 3H, Me); 2.67 (t, 2H, H_3’, J_3’-2’

=

2H, H_2’, J_2’-1’= J_2’-3’= 7Hz); 2.22 (s, 6H, H_4’); 2.35 (t, 2H,

2

7Hz); 2.78 (dd, 1H, H_10ꢁ, J = 15Hz, J_10ꢁ-10a=12Hz); 3.26

H_3’,J_3’-2’= 7Hz); 2.83 (dd, 1H, H_10ꢁ, J = 15Hz, J_10ꢁ-10a

=

(dd, 1H, H_10ꢂ, ²J = 15Hz, J_10ꢂ-10a= 5Hz); 3.68 (t, 2H, H_1’, J_1’-

12Hz); 3.26 (dd, 1H, H_10ꢂ, ²J = 15Hz, J_10ꢂ-10a= 5Hz); 3.61 (t,

2H, H_1’, J_1’-2’= 7Hz); 4.07 (dd, 1H, H_10a, J_10a-10ꢁ= 12Hz, J_10a-

_10ꢂ= 5Hz); 4.42 (d, 1H, H₅, ²J = 17Hz); 5.01 (d, 1H, H₅, ²J =

17Hz) ; 7.1-7.3 (m, 4H, H_aro); ¹³C NMR 75 MHz (CDCl₃),

ꢀ(ppm) : 26.1 (C_3’); 30.8 (C₁₀); 37.1 (C_1’) ; 41.7 (C₅) ; 45.7

(C_4’) ; 54.7 (C_10a) ; 56.7 (C_2’) ; 126.7-127.2-127.4-129.5

(C_aro).

= 7Hz); 3.76 (s, 2H, H_4’); 4.07 (dd, 1H, H_10a, J_10a-10ꢁ

=

2’

2

12Hz_,J_10a-10ꢂ= 5Hz); 4.44 (d, 1H, H₅, J = 17Hz); 5.04 (d,

1H, H₅, ²J = 17Hz); 7.1-7.2 (m, 2H, H_6’,J_6’-5’= 8Hz) ; 7.2-7.4

(m, 6H, H_5’, H₆, H₇, H₈et H₉); ¹³C NMR 75 MHz (CDCl₃),

ꢀ(ppm) : 20.94(C_Me) 28.0 (C_2’); 30.8 (C₁₀); 36.6 (C_1’); 41.5

(C₅); 45.7 (C_3’) 53.4 (C₄); 54.5 (C_10a); 126.5-127.1-127.2-

128.0-128.9-129.3 (C_5’, C_6’, C₆, C₇, C₈et C₉).

2-{3-[(4-methoxybenzyl)methylamino]propyl}-10,10a-dihy-

dro-5H-imidazo[1,5-b]isoquinoline-1,3-dione 5

2-[3-(4-tert-butylbenzylamino)propyl]-10,10a-dihydro-5H-

imidazo[1,5-b]isoquinoline-1,3-dione 46

To a solution of amine 44 (0.49 mmol, 134.4 mg) in an-

hydrous CH₂Cl₂(15mL) was added 4-methoxybenzaldehyde

(1.1 eq, 0.07 mL). After stirring for 15 min, NaBH(OAc)₃(5

eq, 521 mg) and glacial acetic acid (1 eq, 0.03 mL) were

added and the solution was stirred overnight at r.t.. An aque-

ous solution of NaHCO₃(1M, 30 mL) was added. The aque-

ous layer was extracted with CH₂Cl₂(3 x 30mL). The or-

ganic layers were combined and dried over MgSO₄. The sol-

vent was evaporated and the residue was purified by TLC

(CH₂Cl₂/MeOH : 95/5) to yield expected compound 5 as a

yellow oil (181 mg, 94 % yield). TLC (CH₂Cl₂/MeOH :

95/5) Rf = 0.4; HPLC (TSK gel, 10 min) : tr = 4.5min ;

To a stirred solution of 42 (0.38 mmol, 135 mg) in

MeOH (5 mL) was added an aqueous solution of HCl (12N,

3 eq, 0.095mL) and the mixture was stirred for 2.5 h at r.t..

The solvent was evaporated and the crude was diluted with

EtOH (5 mL). 4-Terbutylbenzaldehyde (1.1 eq, 67 mg), TEA

(4 eq, 0.211mL) and molecular sieves 3Å were added. The

solution was stirred for 3 h and then cooled at 0°C. NaBH₄(5

eq, 71 mg) was added portionwise and the mixture was al-

lowed to warm to r.t. and stirred overnight. Water (10 mL)

was added and the solution was filtered throught celite. The

solvent was evaporated. NaOH (1M, 10 mL) was added to

the crude. The aqueous layer was extracted with CH₂Cl₂(3 x

20 mL). The organic layers were combined and dried over

MgSO₄. The solvent was evaporated and the residue was

purified by TLC (CH₂Cl₂/MeOH : 95/5) to yield expected

compound 46 as an oil (46 mg, 30 % yield). TLC

(CH₂Cl₂/MeOH : 98/2) Rf = 0.5; HPLC (TSK gel, 10 min) :

tr = 5.7 min; P_HPLC= 93 %; ES-SM: 406.2 [M+H]⁺; ¹H NMR

300 MHz (CDCl₃), ꢀ(ppm) : 1.21 (s, 9H terButyl); 1.76

P_HPLC= 99 %; HPLC (C4, 40 min) : tr = 23.8 min ; P_HPLC

=

1

98 %; MALDI-TOF : 394.3 [M+H]⁺; H NMR 300 MHz

(CDCl₃), ꢀ(ppm) : 1.86 (quint, 2H, H_2’, J_2’-3’= J_2’-1’= 7Hz);

2.17 (s, 3H, H_4’); 2.42 (t, 2H, H_3’, J_3’-2’= 7Hz); 2.76 (dd, 1H,

2

H_10ꢁ, J_10ꢁ-10a= 12Hz, J = 15Hz); 3.24 (dd, 1H, H_10ꢂ, J =

15Hz, J_10ꢂ-10a= 5Hz); 3.42 (s, 2H, H_5’); 3.62 (t, 2H, H_1’,J_1’-2’

= 7Hz); 3.75 (s, 3H, OCH₃); 4.03 (dd, 1H, H_10a, J_10a-10ꢂ

=

2

5Hz, J_10a-10ꢁ= 12Hz); 4.40 (d, 1H, H₅, J = 16Hz); 5.02 (d,

1H, H₅, ²J= 16Hz) ; 6.7-6.8 (m, 2H, H_7’et H_8’, J_7’-6’= 6,6Hz,

J_7’-7’= 3Hz) ; 7.2-7.3 (m, 6H, H_6’, H₆, H₇, H₈et H₉); ¹³C

NMR 75 MHz (CDCl₃), ꢀ(ppm) : 25.6 (C_2’) ; 30.7 (C₁₀) ;

37.1 (C_1’) ; 41.5 (C₅) ; 41.7 (C_4’) ; 54.2 (C_3’) ; 54.5 (C_10a) ;

(quint, 2H, H_2’, J_2’-1’= J_2’-3’= 7Hz); 2.58 (t, 2H, H_3’, J_3’-2’

=

2

7Hz); 2.71 (dd, 1H, H_10ꢁ, J = 15Hz, J_10ꢁ-10a= 12Hz); 3.16

(dd, 1H, H_10ꢂ, ²J = 15Hz, J_10ꢂ-10a= 5Hz); 3.58 (t, 2H, H_1’, J_1’-

_2’= 7Hz); 3.65 (s, 2H, H_4’); 3.96 (dd, 1H, H_10a, J_10a-10ꢂ= 5Hz,

J

_10a-10ꢁ= 12Hz); 4.32 (d, 1H, H₅, ²J = 17Hz); 4.94 (d, 1H, H₅,

New Synthesis of Tic-Hydantoins Sigma-1 Ligands and Pharmacological Evaluation

Medicinal Chemistry, 2010, Vol. 6, No. 6 365

²J = 17Hz); 7.1-7.3 (m, 8H, H_aro); ¹³C NMR 75 MHz

(CDCl₃), ꢀ(ppm) : 28.3 (C_2’); 30.8 (C₁₀); 31.3(C_terbutyl); 36.7

(C_1’); 41.6 (C₅); 46.1 (C_3’) 53.5 (C₄); 54.6 (C_10a); 125.2-

126.6-127.1-127.3-127.8-129.4 (C_aro).

NMR 75 MHz (CDCl₃), ꢀ(ppm) : 21.1(C_8’); 26.0 (C_2’) ; 31.1

(C₁₀) ; 37.4 (C_1’) ; 41.9 (C₅) ; 42.1 (C_4’) ; 54.6 (C_3’) ; 54.9

(C_10a) ; 62.2 (C_5’); 124.9-126.9-127.4-127.6-129.1-129.3-

129.7 (C_6’, C_7’, C₆, C₇, C₈et C₉).

2-[3-(4-nitrobenzylamino)propyl]-10,10a-dihydro-5H-imid-

azo[1,5-b]isoquinoline-1,3-dione 47

2-{3-[(4-tert-butylbenzyl)methylamino]propyl}-10,10a-dihy-

dro-5H-imidazo[1,5-b]isoquinoline-1,3-dione 4

To a stirred solution of 42 (0.42 mmol, 150 mg) in

MeOH (5 mL) was added an aqueous solution of HCl (12N,

3 eq, 0.105mL) and the mixture was stirred for 2.5 h at r.t.

The solvent was evaporated and the crude was diluted with

EtOH (5 mL). 4-Nitrobenzaldehyde (1.1 eq, 69 mg), TEA (4

eq, 0.235mL) and molecular sieves 3Å were added. The so-

lution was stirred for 3 h and then cooled to 0°C. NaBH₄(5

eq, 79 mg) was added portionwise and the mixture is allowed

to warm to r.t. and stirred overnight. Water (10 mL) was

added and the solution was filtered throught celite. The sol-

vent was evaporated. NaOH (1M, 10 mL) was added to the

crude. The aqueous layer was extracted with CH₂Cl₂(3 x 20

mL). The organic layers were combined and dried over

MgSO₄. The solvent was evaporated and the residue was

purified by TLC (CH₂Cl₂/MeOH : 95/5) to yield expected

compound 47 as a white solid (83 mg, 50 % yield). TLC

(CH₂Cl₂/MeOH : 95/5) Rf = 0.5; HPLC (TSK gel, 10 min) :

tr = 4.6min; P_HPLC> 99 %; ES-MS: 395.1 [M+H]⁺; ¹H NMR

300 MHz (CDCl₃), ꢀ(ppm) : 1.81 (quint, 2H, H_2’, J_2’-1’= J_2’-3’

= 7Hz); 2.58 (t, 2H, H_3’, J_3’-2’= 7Hz); 2.70 (dd, 1H, H_10ꢁ, ²J =

15Hz, J_10ꢁ-10a= 12Hz); 3.19 (dd, 1H, H_10ꢂ, ²J = 15Hz, J_10ꢂ-10a

= 5Hz); 3.64 (t, 2H, H_1’, J_1’-2’= 7Hz); 3.81 (s, 2H, H_4’); 4.01

(dd, 1H, H_10a, J_10a-10ꢁ= 12Hz_,J_10a-10ꢂ= 5Hz); 4.35 (d, 1H, H₅,

²J = 17Hz); 4.95 (d, 1H, H₅, ²J = 17Hz); 7.1-7.3 (m, 4H, H₆,

H₇, H₈et H₉); 7.4-7.5 (m, 2H, H_6’,J_6’-5’= 9Hz); 8.0-8.1 (m,

2H, H_5’,J_5’-6’= 9Hz, J_5’-5’= 2Hz,); ¹³C NMR 75 MHz

(CDCl₃), ꢀ(ppm) : 31.2 (C_2’); 33.9 (C₁₀); 39.4 (C_1’); 44.6

(C₅); 49.0 (C_3’) 56.1 (C₄); 57.7 (C_10a); 126.5 (C_5’); 129.6-

130.3-130.4-132.4 (C₆, C₇, C₈et C₉) ; 131.7 (C_6’).

To a solution of 46 (0.11 mmol, 45 mg) in CH₃CN (2

mL) was added formaldehyde (5 eq, 0.043mL) and sodium

cyanoborohydride (1.6 eq, 11 mg) at 0°C. After stirring for

15 min at r.t., glacial acetic acid (1 mL) was added to the

solution until pH reached 6-7 and the reaction was stirred for

further 45 min. The solvent was evaporated and aqueous

solution of de NaOH (1M, 1 mL) was added. The aqueous

layer was extracted with CH₂Cl₂(3 x 20mL). The organic

layers were combined and dried over MgSO₄. The solvent

was evaporated and the residue was purified by TLC

(CH₂Cl₂/MeOH : 94/6) to yield expected compound 4 as an

oil (19 mg, 41 % yield). TLC (CH₂Cl₂/MeOH : 95/5) Rf =

0.3; HPLC (TSK gel, 10 min) : tr = 5.7 min; P_HPLC= 99 %;

HPLC (C4, 40 min) : tr = 14 .2 min ; P_HPLC= 99 %; ES-MS:

1

420.2 [M+H]⁺; H NMR 300 MHz (CDCl₃), ꢀ(ppm) : 1.28

(s, 9H, H_6’); 1.87 (quint, 2H, H_2’, J_2’-3’= J_2’-1’= 7Hz); 2.18 (s,

3H, H_4’); 2.44 (t, 2H, H_3’, J_3’-2’= 7Hz); 2.80 (dd, 1H, H_10ꢁ, ²J

= 15Hz, J_10ꢁ-10a= 12Hz); 3.25 (dd, 1H, H_10ꢂ, ²J = 15Hz, J_10ꢂ-

_10a= 5Hz); 3.44 (s, 2H, H_5’); 3.63 (t, 2H, H_1’, J_1’-2’= 7Hz);

4.04 (dd, 1H, H_10a, J_10a-10ꢁ= 12Hz, J_10a-10ꢂ= 5Hz); 4.41 (d,

1H, H₅, ²J = 16Hz); 5.02 (d, 1H, H₅, ²J = 16Hz) ; 7.1-7.3 (m,

8H, H_aro); ¹³C NMR 75 MHz (CDCl₃), ꢀ(ppm) : 26.1 (C_2’) ;

31.2 (C₁₀) ; 31.7 (C_6’); 37.5 (C_1’) ; 41.9 (C₅) ;42.2 (C_4’) ; 54.9

(C_3’) ; 55.0(C_10a) ; 62.1 (C_5’); 125.3-126,9-127.5-127.6-

127.6-129.0-129.7 (C_aro).

2-{3-[methyl(4-nitrobenzyl)amino]propyl}-10,10a-dihydro-

5H-imidazo[1,5-b]isoquinoline-1,3-dione 6

To a solution of 47 (0.13 mmol, 45 mg) in CH₃CN (2

mL) was added formaldehyde (5 eq, 0.047mL) and sodium

cyanoborohydride (1.6 eq, 13 mg) at 0°C. After stirring for

15 min at r.t., glacial acetic acid (1 mL) was added to the

solution until pH reached 6-7 and the reaction was stirred for

further45 min. The solvent was evaporated and aqueous so-

lution of de NaOH 1M (1 mL) was added. The aqueous layer

was extracted with CH₂Cl₂(3 x 20mL). The organic layers

were combined and dried over MgSO₄. The solvent was

evaporated and the residue was purified by TLC

(CH₂Cl₂/MeOH : 94/6) to yield expected compound 6 as an

oil (12 mg, 23 % yield). TLC (CH₂Cl₂/MeOH : 95/5) Rf =

0.5; HPLC (TSK gel, 10 min) : tr = 4.6 min; P_HPLC= 99 %;

HPLC (C4, 40 min) : tr = 10.2 min ; P_HPLC= 99 %; ES-MS:

2-{3-[methyl-(4-methylbenzyl)amino]propyl}-10,10a-dihydro-

5H-imidazo[1,5-b]isoquinoline-1,3-dione 3

To a solution of 45 (0.25 mmol, 90 mg) in CH₃CN (2

mL) was added formaldehyde (5 eq, 0.093mL) and sodium

cyanoborohydride (1.6 eq, 25 mg) at 0°C. After stirring for

15 min at r.t., glacial acetic acid (1 mL) was added to the

solution until pH reached 6-7 and the reaction was stirred for

further 45 min. The solvent was evaporated and aqueous

solution of NaOH (1M, 1 mL) was added. The aqueous layer

was extracted with CH₂Cl₂(3 x 20mL). The organic layers

were combined and dried over MgSO₄. The solvent was

evaporated and the residue was purified by TLC

(CH₂Cl₂/MeOH : 93/7) to yield expected compound 3 as an

oil (21 mg, 23 % yield). TLC (CH₂Cl₂/MeOH : 95/5) Rf =

0.4; HPLC (TSK gel, 10 min) : tr = 4.8 min; P_HPLC= 90 %;

HPLC (C4, 40 min) : tr = 11.3 min ; P_HPLC= 98 %; ES-MS:

1

409.1 [M+H]⁺; H NMR 300 MHz (CDCl₃), ꢀ(ppm) : 1.88

(quint, 2H, H_2’, J_2’-1’= J_2’-3’= 7Hz); 2.18 (s, 3H, H_4’); 2.46 (t,

2H, H_3’, J_3’-2’= 7Hz); 2.76 (dd, 1H, H_10ꢁ, ²J = 15Hz, J_10ꢁ-10a

=

12Hz); 3.25 (dd, 1H, H_10ꢂ, ²J = 15Hz, J_10ꢂ-10a= 5Hz); 3.56 (s,

1

378.1 [M+H]⁺; H NMR 300 MHz (CDCl₃), ꢀ(ppm) : 1.84

2H, H_5’); 3.65 (t, 2H, H_1’, J_1’-2’= 7Hz); 4.06 (dd, 1H, H_10a,

(quint, 2H, H_2’, J_2’-3’= J_2’-1’= 7Hz); 2.17 (s, 3H, H_4’); 2.27 (s,

3H, H_8’); 2.42 (t, 2H, H_3’, J_3’-2’= 7Hz); 2.75 (dd, 1H, H_10ꢁ, ²J

=15Hz, J_10ꢁ-10a= 12Hz); 3.23 (dd, 1H, H_10ꢂ, ²J = 15Hz, J_10ꢂ-10a

= 5Hz); 3.43 (s, 2H, H_5’); 3.62 (t, 2H, H_1’, J_1’-2’= 7Hz); 4.03

(dd, 1H, H_10a, J_10a-10ꢁ= 12Hz, J_10a-10ꢂ= 5Hz); 4.40 (d, 1H, H₅,

²J = 16Hz); 5.02 (d, 1H, H₅, ²J = 16Hz) ; 7.0-7.1 (m, 2H, H_6’,

J_6’-5’= 8Hz) ; 7.1-7.3 (m, 6H, H_5’, H₆, H₇, H₈et H₉); ¹³C

J_10a-10ꢁ= 12Hz, J_10a-10ꢂ= 5Hz); 4.41 (d, 1H, H₅, ²J =

2

16Hz); 5.02 (d, 1H, H₅, J = 16Hz) ; 7.1-7.3 (m, 4H, H₆, H₇,

H₈et H₉); 7.4-7.5 (m, 2H, H_7’, J_7’-6’= 9Hz, J_7’-7’= 2Hz) ; 8.1-

8.2 (m, 2H, H_6’, J_6’-7’= 9Hz, J_6’-6’= 2Hz) ¹³C NMR 75 MHz

(CDCl₃), ꢀ(ppm) : 26.3 (C_2’) ; 31.2 (C₁₀) ; 37.3 (C_1’) ; 42,0

(C₅) ; 42.4 (C_4’) ; 55.0 (C_10a) ; 55.3 (C_3’) ; 62.0 (C_5’); 123.9

(C_7’) 127.0-127.6-127.8-129.8 (C_6’, C₆, C₇, C₈et C₉).

366 Medicinal Chemistry, 2010, Vol. 6, No. 6

Toussaint et al.

evaporated and the residue was purified by TLC

(EtOAc/cyclohexane : 2/8) to yield expected compound 12

as an oil (104 mg, 41 % yield). TLC (AcOEt/Cyclohexane :

3/7) Rf = 0.8; HPLC (TSK gel, 10 min) : tr = 5.12min ;

2-(3-diethylaminopropyl)-10,10a-dihydro-5H-imidazo[1,5-

b]isoquinoline-1,3-dione 10

To a solution of amine 43 (0.39 mmol, 103 mg,) in

CH₂Cl₂(5 mL) were added acetaldehyde (3 eq, 0.068 mL)

and NaBH(OAc)₃(3 eq, 253 mg). The mixture was stirred

for 4 h at r.t.. An aqueous solution of NaOH 1M (5 mL) was

added and the solution was stirred for 15 min. The aqueous

layer was extracted with CH₂Cl₂(3 x 15 mL) and the organic

layers combined and dried over MgSO₄. The solvent was

evaporated and the residue was purified by TLC

(EtOAc/MeOH : 94/4) to yield expected compound 10 as an

oil (32 mg, 26 % yield). TLC (AcOEt/MeOH : 94/6) Rf =

0.2; HPLC (TSK gel, 10 min) : tr = 3.9 min ; P_HPLC= 98 %;

HPLC (C4, 40 min) : tr = 10.7 min ; P_HPLC= 98 %; MALDI-

P_HPLC= 95 %, HPLC (C4, 40 min) : tr = 20.80min ; P_HPLC

=

1

97 %; MALDI-TOF : 440.2 [M+H]⁺; H NMR 300 MHz

(CDCl₃), ꢀ(ppm) : 1.85 (quint, 2H, H_2’, J_2’-3’= J_2’-1’= 7Hz) ;

2.45 (t, 2H, H_3’, J_3’-2’= 7Hz); 2.61 (dd, 1H, H_10ꢁ, J_10ꢁ-10a

12Hz, J = 16Hz); 3.17 (dd, 1H, H_10ꢂ, J = 16Hz, J_10ꢂ-10a

=

2

5Hz); 3.5-3.6 (m, 6H, H_5’et H_1’); 3.96 (dd, 1H, H_10a, J_10a-10ꢂ

2

5Hz, J_10a-10ꢁ= 12Hz); 4.37 (d, 1H, H₅, J = 17Hz); 4.98 (d,

2

1H, H₅, J = 17Hz) ; 7.1-7.3 (m, 14H, H_aro);¹³C NMR 75

MHz (CDCl₃), ꢀ(ppm) : 25.6 (C_2’) ; 31.0 (C₁₀) ; 37.2 (C_1’) ;

41.7 (C₅) ; 41.7 (C_3’) ; 54.7 (C_10a); 58.4 (C_4’) ; 126.8-127.0-

127.3-127.5-128.4-129.1-129.6-129.9 (C_aro).

1

TOF : 316.1 [M+H]⁺; H NMR 300 MHz (CDCl₃), ꢀ(ppm) :

1.01 (t, 6H, H_5’, J_5’-4’= 7Hz);1.82 (quint, 2H, H_2’, J_2’-1’= J_2’-3’

2-{3-[Bis(4-methylbenzyl)amino]propyl}-10,10a-dihydro-5H-

imidazo[1,5-b]isoquinoline-1,3-dione 13

2

= 7Hz); 2.5-2.6 (m, 6H, H_3’et H_4’); 2.82 (dd, 1H, H_10ꢁ, J =

15Hz, J_10ꢁ-10a= 12Hz); 3.27 (dd, 1H, H_10ꢂ, ²J = 15Hz, J_10ꢂ-10a

To a solution of amine 43 (0.57 mmol, 147 mg,) in

CH₂Cl₂(5 mL) were added p-tolualdehyde (3 eq, 0.20 mL)

and NaBH(OAc)₃(3 eq, 362 mg). The mixture was stirred

for 4 h at r.t.. An aqueous solution of NaOH (1M, 5 mL) was

added and the solution was stirred for 15 min. The aqueous

layer was extracted with CH₂Cl₂(3 x 15 mL) and the organic

layers combined and dried over MgSO₄. The solvent was

evaporated and, the residue was purified by TLC

(EtOAc/cyclohexane : 3/7) to yield expected compound 13

as an oil (71 mg, 26 % yield). TLC (AcOEt/Cyclohexane :

3/7) Rf = 0.5; HPLC (TSK gel, 10 min) : tr = 5.7 min ; P_HPLC

= 97 %; HPLC (C4, 40 min) : tr = 28.7 min ; P_HPLC= 90 %;

= 5Hz,); 3.60 (t, 2H, H_1’, J_1’-2’= 7Hz); 4.07 (dd, 1H, H_10a

,

J_10a-10ꢁ= 12Hz, J_10a-10ꢂ= 5Hz); 4.42 (d, 1H, H₅, ²J =

2

17Hz); 5.00 (d, 1H, H₅, J = 17Hz) ; 7.1-7.3 (m, 4H, H_aro);

¹³C NMR 75 MHz (CDCl₃), ꢀ(ppm) : 14.1 (C_5’); 28.1 (C_2’);

33.3 (C₁₀); 40.0 (C_1’) ; 44.1 (C₅) ; 49.2 (C_4’) ; 52.8 (C_3’); 57.3

(C_10a) ; 129.3-129.8 (C_aro).

2-(3-diisobutylaminopropyl)-10,10a-dihydro-5H-imidazo[1,

5-b]isoquinoline-1,3-dione 11

To a solution of amine 43 (0.44 mmol, 115 mg,) in

CH₂Cl₂(5 mL) were added isobutyraldehyde (3 eq, 0.12 mL)

and NaBH(OAc)₃(3 eq, 282 mg). The mixture was stirred

for 4 h at r.t.. An aqueous solution of NaOH (1M, 5 mL) was

added and the solution was stirred for 15 min. The aqueous

layer was extracted with CH₂Cl₂(3 x 15 mL) and the organic

layers combined and dried over MgSO₄. The solvent was

evaporated and the residue was purified by TLC

(CH₂Cl₂/MeOH : 98/2) to yield expected compound 11 as an

oil (86 mg, 48 % yield). TLC (AcOEt/Cyclohexane : 5/5) Rf

= 0.8 ; HPLC (TSK gel, 10 min) : tr = 4.7 min ; P_HPLC= 98

%; HPLC (C4, 40 min) : tr = 12.1 min ; P_HPLC= 98 %;

1

MALDI-TOF : 468.2 [M+H]⁺; H NMR 300 MHz (CDCl₃),

ꢀ(ppm) : 1.86 (quint, 2H, H_2’, J_2’-3’= J_2’-1’= 7Hz) ; 2.25 (s,

6H, H_7’) ; 2.43 (t, 2H, H_3’, J_3’-2’= 7Hz); 2.63 (dd, 1H, H_10ꢁ, ²J

= 16Hz, J_10ꢁ-10a= 12Hz); 3.19 (dd, 1H, H_10ꢂ, ²J = 16Hz, J_10ꢂ-

_10a= 5Hz); 3.5-3.6 (m, 6H, H_4’et H_1’); 3.95 (dd, 1H, H_10a

,

J_10a-10ꢁ= 12Hz, J_10a-10ꢂ= 5Hz); 4.39 (d, 1H, H₅, ²J =

17Hz); 4.98 (d, 1H, H₅, ²J = 17Hz) ; 7.0-7.1 (m, 4H, H_6’,H_8’,

J

_6’-5’= 7,8 Hz) ; 7.2-7.3 (m, 8H, H_5’, H₆, H₇, H₈et H₉); ¹³C

NMR 75 MHz (CDCl₃), ꢀ(ppm) : 16.4 (C_7’) ; 20.7 (C_2’) ; 26.2

(C₁₀) ; 32.4 (C_1’) ; 36.9 (C₅) ; 45.3 (C_3’) ; 49.9 (C_10a) ; 53.1

(C_4’) ; 122.0-122.5-122.7-124.2-124.8-125.0 (C_aro).

1

MALDI-TOF : 372.3 [M+H]⁺; H NMR 300 MHz (CDCl₃),

ꢀ(ppm) : 0.8-0.9 (m, 12H, H_6’); 1.6-1.7 (m, 4H, H_5’et H_2’);

2.05 (d, 4H, H_4’,J_4’-5’= 7Hz); 2.39 (t, 2H, H_3’, J_3’-2’= 7Hz);

2-{3-[bis(4-tert-butylbenzyl)amino]propyl}-10,10a-dihydro-

5H-imidazo[1,5-b]isoquinoline-1,3-dione 14

2.81 (dd, 1H, H_10ꢁ, ²J = 15Hz, J_10ꢁ-10a= 12Hz); 3.27 (dd, 1H,

2

H_10ꢂ, J = 15Hz, J_10ꢂ-10a= 5Hz); 3.5-3.6 (m, 2H, H_1’,J_1’-2’

=

To a solution of amine 43 (0.57 mmol, 149 mg,) in

CH₂Cl₂(5 mL) were added 4-tert-butylbenzaldehyde (3 eq,

0.29 mL) and NaBH(OAc)₃(3 eq, 376 mg). The mixture was

stirred for 4 h at r.t.. An aqueous solution of NaOH (1M, 5

mL) was added and the solution was stirred for 15 min. The

aqueous layer was extracted with CH₂Cl₂(3 x 15 mL) and

the organic layers combined and dried over MgSO₄. The

solvent was evaporated and the residue was purified by TLC

(EtOAc/cyclohexane : 3/7) to yield expected compound 14

as an oil (92 mg, 29 % yield). TLC (AcOEt/Cyclohexane :

3/7) Rf = 0.6 ; HPLC (TSK gel, 10 min) : tr = 7.2 min ;

P_HPLC= 98 %; HPLC (C4, 40 min) : tr = 18.1min ; P_HPLC= 92

%; MALDI-TOF : 552.2 [M+H]⁺; ¹H NMR 300 MHz

(CDCl₃), ꢀ(ppm) : 1.28 (s, 18H, H_7’) ; 1.88 (quint, 2H, H_2’,

J_2’-3’= J_2’-1’= 7Hz) ; 2.48 (t, 2H, H_3’, J_3’-2’= 7Hz); 2.75 (dd,

1H, H_10ꢁ, ²J = 16Hz, J_10ꢁ-10a= 12Hz); 3.23 (dd, 1H, H_10ꢂ, ²J =

16Hz, J_10ꢂ-10a= 5Hz); 3.5-3.6 (m, 6H, H_4’et H_1’); 3.98 (dd,

7Hz); 4.41 (dd, 1H, H_10a, J_10a-10ꢁ= 12Hz, J_10a-10ꢂ= 5Hz); 4.41

2

(d, 1H, H₅, J = 17Hz); 5.03 (d, 1H, H₅, J = 17Hz) ; 7.2-7.3

(m, 4H, H_aro); ¹³C NMR 75 MHz (CDCl₃), ꢀ(ppm) : 20.8

(C_6’); 25.9 (C_2’); 26.4 (C_5’) ; 30.8 (C₁₀) ; 37.4 (C_1’) ; 41.5

(C₅) ; 52.5 (C_3’) ; 54.5 (C_10a) ; 63.7 (C_4’) ; 126.5-127.0-127.2-

129.3 (C_aro).

2-(3-dibenzylaminopropyl)-10,10a-dihydro-5H-imidazo[1,5-b]

isoquinoline-1,3-dione 12

To a solution of amine 43 (0.58 mmol, 152 mg,) in

CH₂Cl₂(5 mL) were added benzaldehyde (3 eq, 0.18 mL)

and NaBH(OAc)₃(3 eq, 373 mg). The mixture was stirred

for 4 h at r.t.. An aqueous solution of NaOH 1M (5 mL) was

added and the solution was stirred for 15 min. The aqueous

layer was extracted with CH₂Cl₂(3 x 15 mL) and the organic

layers combined and dried over MgSO₄. The solvent was

New Synthesis of Tic-Hydantoins Sigma-1 Ligands and Pharmacological Evaluation

Medicinal Chemistry, 2010, Vol. 6, No. 6 367

1H, H_10a, J_{10a -10ꢀ}= 12Hz, J_10a-10ꢁ= 5Hz); 4.39 (d, 1H, H₅, ²J =

2-[3-(bis(cyclohexylmethyl)amino)propyl]-10,10a-dihydro-

5H-imidazo[1,5-b]isoquinoline-1,3-dione 18

2

17Hz); 5.00 (d, 1H, H₅, J = 17Hz) ; 7.2-7.3 (m, 12H, H_5’,

H_6’, H₆, H₇, H₈et H₉) ; ¹³C NMR 75 MHz (CDCl₃), ꢂ(ppm) :

24.6 (C_2’) ; 30.1 (C₁₀) ; 30.6 (C_7’) ; 33.6 (C_1’) ; 40.8 (C₅) ;

49.5 (C_3’) ; 53.8 (C_10a) ; 56.8 (C_4’) ; 124.2-125.8-126.4-

126.5-127.6-128.6 (C_aro).

To a solution of amine 43 (0.34 mmol, 88 mg,) in CH₂Cl₂

(5 mL) were added cyclohexanecarboxaldehyde (3 eq, 0.12

mL) and NaBH(OAc)₃(3 eq, 217 mg). The mixture was

stirred for 4 h at r.t.. An aqueous solution of NaOH (1M, 5

mL) was added and the solution was stirred for 15 min. The

aqueous layer was extracted with CH₂Cl₂(3 x 15 mL) and

the organic layers combined and dried over MgSO₄. The

solvent was evaporated and the residue was purified by TLC

(EtOAc/cyclohexane : 2/8) to yield expected compound 18

as an oil (86 mg, 56 % yield). TLC (AcOEt/Cyclohexane :

2/8) Rf = 0.4 ; HPLC (TSK gel, 10 min) : tr = 6.5 min ;

2-{3-[bis(4-methoxybenzyl)amino]propyl}-10,10a-dihydro-

5H-imidazo[1,5-b]isoquinoline-1,3-dione 15

To a solution of amine 43 (0.69 mmol, 177 mg,) in

CH₂Cl₂(5 mL) were added 4-methoxybenzaldehyde (3 eq,

0.25 mL) and NaBH(OAc)₃(3 eq, 436 mg). The mixture was

stirred for 4 h at r.t.. An aqueous solution of NaOH (1M, 5

mL) was added and the solution was stirred for 15 min. The

aqueous layer was extracted with CH₂Cl₂(3 x 15 mL) and

the organic layers combined and dried over MgSO₄. The

solvent was evaporated and the residue was purified by TLC

(EtOAc/cyclohexane : 3/7) to yield expected compound 15

as an oil (146 mg, 42 % yield). TLC (AcOEt/ Cyclohexane :

3/7) Rf = 0.3 ; HPLC (TSK gel, 10 min) : tr = 5.2min ; P_HPLC

= 96 %; HPLC (C4, 40 min) : tr = 22.3min ; P_HPLC= 98 %;

P_HPLC= 98 %; HPLC (C4, 40 min) : tr = 15.9 min ; P_HPLC

=

1

98 %; MALDI-TOF : 452.2 [M+H]⁺; H NMR 300 MHz

(CDCl₃), ꢂ(ppm) : 0.7-0.9 (m, 4H, H_6’a); 1.1-1.3 (m, 3H, H_7’a

et H_8’a); 1.3-1.5 (m, 2H, H_5’a); 1.6-1.8 (m, 12H, H_6’e, H_7’e,

H_8’eet H_2’) ; 2.08 (d, 2x2H, H_4’, J_4’-5’= 7Hz) ; 2.36 (t, 2H,

2

H_3’, J_3’-2’= 7Hz) ; 2.82 (dd, 1H, H_10ꢀ, J = 16Hz, J_10ꢀ-10a

=

12Hz); 3.27 (dd, 1H, H_10ꢁ, ²J = 16Hz, J_10ꢁ-10a= 5Hz); 3.58 (t,

2H, H_1’, J_1’-2’= 7Hz); 4.06 (dd, 1H, H_10a, J_10a-10ꢀ= 12Hz_,J_10a-

_10ꢁ= 5Hz); 4.41 (d, 1H, H₅, ²J = 17Hz) ; 5.03 (d, 1H, H₅, ²J =

17Hz) ; 7.2-7.3 (m, 4H, H_aro); ¹³C NMR 75 MHz (CDCl₃),

ꢂ(ppm) : 28.8 et 29.4 (C_7’et C_8’) ; 33.6 (C₁₀) ; 34.7 (C_6’) ;

38.7 (C_5’) ; 40.2 (C_1’) ; 44.1 (C₅); 54.2 (C_10a) ; 55.1 (C_3’) ;

64.8 (C_4’) ; 129.3-129.9-132.0 (C_aro).

1

MALDI-TOF : 500.2 [M+H]⁺; H NMR 300 MHz (CDCl₃),

ꢂ(ppm) : 1.83 (quint, 2H, H_2’, J_2’-3’= J_2’-1’= 7Hz); 2.44 (t,

2H, H_3’, J_3’-2’= 7Hz); 2.66 (dd, 1H, H_10ꢀ, ²J = 15Hz, J_10ꢀ-10a

=

12Hz); 3.20 (dd, 1H, H_10ꢁ, ²J = 15Hz, J_10ꢁ-10a= 5Hz); 3.5-3.6

(m, 6H, H_4’et H_1’); 3.74 (s, 2x3H, OCH₃); 3,97 (dd, 1H,

2

H

_10a, J_10a-10ꢀ= 12Hz, J_10a-10ꢁ= 5Hz); 4.39 (d, 1H, H₅, J =

2-(3-benzylaminopropyl)-10,10a-dihydro-5H-imidazo[1,5-b]

isoquinoline-1,3-dione 48

17Hz); 4.99 (d, 1H, H₅, ²J = 17Hz) ; 6.8-6.9 (m, 4H, H_6’J_6’-5’

= 5Hz, J_6’-6’= 3Hz) ; 7.2-7.3 (m, 12H, H_6’, H_9’, H₆, H₇, H₈et

H₉); ¹³C NMR 75 MHz (CDCl₃), ꢂ(ppm) : 21.5 (C_2’) ; 27.1

(C₁₀) ; 33.3 (C_1’) ; 37.8 (C₅) ; 46.4 (C_3’) ; 50.8 (C_10a) ; 51.4

(OCH₃) ; 53.5 (C_4’) ; 120.1-122.9-123.4-123.6-125.7-126.3

(C_aro).

To a solution of 43 (1.61 mmol, 418 mg) in CH₂Cl₂(10

mL) was added benzaldehyde (1.1 eq, 0.18 mL), TEA (0.4

eq, 0.09mL) and molecular sieves 3Å. The mixture was

stirred for 3 h at r.t. and then cooled to 0°C and NaBH₄(5

eq, 305 mg) was added portionwise. After an additional stir-

ring for 1.5 h, water was added. After filtration, the aqueous

layer was extracted with CH₂Cl₂(3 x 10 mL) and the organic

layers were combined and dried over MgSO₄. The solvent

was evaporated and the residue was purified by TLC

(CH₂Cl₂/MeOH : 95/5) to yield expected compound 48 as an

oil (119 mg, 21 % yield). TLC (CH₂Cl₂/MeOH : 95/5) Rf =

0.4; HPLC (TSK gel, 10 min) : tr = 4.7min ; P_HPLC= 98 %;

2-{3-[bis(4-fluorobenzyl)amino]propyl}-10,10a-dihydro-5H-

imidazo[1,5-b]isoquinoline-1,3-dione 17

To a solution of amine 43 (0.44 mmol, 115 mg,) in

CH₂Cl₂(5 mL) were added 4-fluorobenzaldehyde (3 eq, 0.14

mL) and NaBH(OAc)₃(3 eq, 282 mg). The mixture was

stirred for 4 h at r.t.. An aqueous solution of NaOH (1M, 5

mL) was added and the solution was stirred for 15 min. The

aqueous layer was extracted with CH₂Cl₂(3 x 15 mL) and

the organic layers combined and dried over MgSO₄. The

solvent was evaporated and the residue was purified by TLC

(EtOAc/cyclohexane : 2/8) to yield expected compound 17

as an oil (117 mg, 56 % yield). TLC (AcOEt/Cyclohexane :

2/8) Rf = 0.2 ; HPLC (TSK gel, 10 min) : tr = 5.4 min ;

1

MALDI-TOF : 350.2 [M+H]⁺; H NMR 300 MHz (CDCl₃),

ꢂ(ppm) : 1.86 (quint, 2H, H_2’, J_2’-3’= J_2’-1’= 7Hz); 2.63 (t,

2H, H_3’, J_3’-2’= 7Hz); 2.6-2.7 (m, 1H, H_10ꢀ); 3.19 (dd, 1H,

H_10ꢁ, ²J = 15Hz, J_10ꢁ-10a= 5Hz); 3.63 (t, 2H, H_1’, J_1’-2’= 7Hz);

3.76 (s, 2H, H_4’); 4.03 (dd, 1H, H_10a, J_10a-10ꢀ= 12Hz, J_10a-10ꢁ

=

2

5Hz); 4.37 (d, 1H, H₅, J = 17Hz); 4.98 (d, 1H, H₅, J =

17Hz) ; 7.2-7.3 (m, 9H, H_aro); ¹³C NMR 75 MHz (CDCl₃),

ꢂ(ppm) : 27.9 (C_2’) ; 30.7 (C₁₀) ; 36.5 (C_1’) ; 41.5 (C₅) ; 45.7

(C_3’) ; 53.6 (C_4’) ; 54.5 (C_10a) ; 126.5-126.9-127.1-127.2-

128.2-128.3-129.3 (C_aro).

P

_HPLC= 98 %; HPLC (C4, 40 min) : tr = 18.9min ; P_HPLC= 97

%; MALDI-TOF : 476.2 [M+H]⁺; ¹H NMR 300 MHz

(CDCl₃), (ppm) : 1.84 (quint, 2H, H_2’, J_2’-3’= J_2’-1’= 7Hz) ;

2

2.43 (t, 2H, H_3’, J_3’-2’= 7Hz); 2.67 (dd, 1H, H_10ꢀ, J = 16Hz,

J_10ꢀ-10a= 12Hz); 3.21 (dd, 1H, H_10ꢁ, J = 16Hz, J_10ꢁ-10a

2-[3-(benzylethylamino)propyl]-10,10a-dihydro-5H-

imidazo[1,5-b]isoquinoline-1,3-dione 19

2

=

5Hz); 3.5-3.6 (m, 6H, H_4’et H_1’); 4.00 (dd, 1H, H_10a, J_10a-10ꢀ

= 12Hz, J_10a-10ꢁ= 5Hz); 4.38 (d, 1H, H₅, ²J = 17Hz); 4.99 (d,

1H, H₅, ²J = 17Hz) ; 6.9-7.0 (tt, 4H, H_6’, J_6’-5’= J_6’-F= 8,7Hz,

After stirring for 15 min, to a solution of amine 48 (0.29

mmol, 100 mg) and acetaldehyde (2 eq, 0.032 mL) in

CH₂Cl₂(5mL), were added NaBH(OAc)₃(5 eq, 297 mg) and

glacial acetic acid (1 eq, 0.017 mL) and the solution was

stirred overnight at r.t.. An aqueous solution of NaHCO₃

(1M, 5 mL) was added and the aqueous layer was extracted

J

_6’-6’= 2,8Hz) ; 7.2-7.3 (m, 8H, H_5’, H₆, H₇, H₈et H₉); ¹³C

NMR 75 MHz (CDCl₃), (ppm) : 23.8 (C_2’) ; 29.2 (C₁₀) ; 35.2

(C_1’) ; 39.9 (C₅) ; 48.5 (C_3’) ; 52.9 (C_10a); 55.7 (C_4’) ; 113.17-

113.18 (C_5’, J_C-F= 21Hz); 126.6-130.5 (C_6’, C₆, C₇, C₈et C₉).

368 Medicinal Chemistry, 2010, Vol. 6, No. 6

Toussaint et al.

with CH₂Cl₂(3 x 10 mL). The organic layers were combined

and dried over MgSO₄. The solvent was evaporated and the

residue was purified by TLC (CH₂Cl₂/EtOAc/MeOH/

NH₄OH : 7/2.5/0.5/0.25) to yield expected compound 19 as

yellow oil (20 mg, 18 % yield). TLC (CH₂Cl₂/MeOH : 95/5)

Rf = 0.5; HPLC (TSK gel, 10 min): tr = 4.1 min; P_HPLC= 85

%; HPLC (C4, 40 min): tr = 14.1 min; P_HPLC= 98 %; MAL-

DI-TOF : 378.2 [M+H]⁺; ¹H NMR 300 MHz (CDCl₃),

ꢀ(ppm) : 1.03 (t, 3H, H_6’, J_6’-5’= 7Hz); 1.81 (quint, 2H, H_2’,

J_2’-3’= J_2’-1’= 7Hz); 2.47 (t, 2H, H_3’, J_3’-2’= 7Hz); 2.49 (q,

%; HPLC (C4, 40 min): tr = 13.1min; P_HPLC= 98 %;

1

MALDI-TOF : 362.1 [M+H]⁺; H NMR 300 MHz (CDCl₃),

ꢀ(ppm): 1.93 (quint, 2H, H_2’, J_2’-3’= J_2’-1’= 7Hz); 2.7-2.8 (m,

2

3H, H_3’et H_10ꢁ); 3.20 (dd, 1H, H_10ꢂ, J = 15Hz, J_10ꢂ-10a

=

5Hz); 3.69 (t, 2H, H_1’, J_1’-2’= 7Hz); 3.91 (s, 4H, H_4’); 4.02

(dd, 1H, H_10a, J_10a-10ꢁ= 12Hz, J_10a-10ꢂ= 5Hz); 4.36 (d 1H, H₅,

2

²J = 17Hz); 4.98 (d, 1H, H₅, J = 17Hz) ; 7.1-7.3 (m, 8H,

H_aro); ¹³C NMR 75 MHz (CDCl₃), ꢀ(ppm) : 27.1 (C_2’) ; 30.6

(C₁₀); 37.2 (C_1’); 41.5 (C₅); 53.4 (C_3’); 54.6 (C_10a); 58.4 (C_4’);

122.2-123.0-126.6-126.7-127.1-127.2-127.5-127.9-129.4 (C_aro).

2H, H_5’, J_5’-6’= 7Hz); 2.71 (dd, 1H, H_10ꢁ, ²J = 15Hz, J_10ꢁ-10a

=

12Hz); 3.22 (dd, 1H, H_10ꢂ, ²J = 15Hz, J_10ꢂ-10a= 5Hz); 3.47 (s,

2-[3-(3,4-dihydro-1H-isoquinolin-2-yl)propyl]-10,10a-dihy-

dro-5H-imidazo[1,5-b]isoquinoline-1,3-dione 22

2H, H_4’); 3.55 (t, 2H, H_1’, J_1’-2’= 7Hz); 4.03 (dd, 1H, H_10a

,

J_10a-10ꢁ= 12Hz, J_10a-10ꢂ= 5Hz); 4.40 (d, 1H, H₅, ²J =

To a solution of 37 (1.1 eq, 329 mg) in CH₂Cl₂(30 mL)

was added tetrahydroisoquinoline (1.15 mmol, 0.152 mL)

and the mixture was stirred for 15 min at r.t.. NaBH(OAc)₃

(5 eq, 1.22 g) and glacial acetic acid (2 eq, 0,067 mL) were

added and the solution was stirred overnight at r.t.. The reac-

tion was quenched with an aqueous solution of NaHCO₃

(30mL) followed by extraction with CH₂Cl₂(3x30mL). The

organic layers were combined and dried over MgSO₄. The

solvent was evaporated and the residue purified by TLC

(CH₂Cl₂/MeOH : 95/5) to yield expected compound 22 as a

white solid (168 mg, 39 % yield). TLC (CH₂Cl₂/MeOH :

9/1) Rf = 0.7; HPLC (TSK gel, 10 min) : tr = 4.5 min ; P_HPLC

= 95 %; HPLC (C4, 40 min) : tr = 16.5 min ; P_HPLC= 95 %;

2

17Hz); 4.98 (d, 1H, H₅, J = 17Hz) ; 7.1-7.3 (m, 9H, H_aro);

¹³C NMR 75 MHz (CDCl₃), ꢀ(ppm) : 11.5 (C_6’); 25.5 (C_2’) ;

30.8 (C₁₀) ; 37.1 (C_1’) ; 41.5 (C₅) ; 47.0 (C_5’) ; 50.1 (C_3’) ;

54.5 (C_10a) ; 57.8 (C_4’) ; 126.5-126.6-127.1-127.2-128.0-

128.8-129.3 (C_aro).

2-[3-(benzylisobutylamino)propyl]-10,10a-dihydro-5H-imi-

dazo[1,5-b]isoquinoline-1,3-dione 20

After stirring for 15 min, to a solution of amine 48 (0.33

mmol, 349 mg) and isobutyraldehyde (2 eq, 0.030 mL) in

CH₂Cl₂(5mL), were added NaBH(OAc)₃(5 eq, 211 mg) and

glacial acetic acid (1 eq, 0.017 mL) and the solution was

stirred overnight at r.t.. An aqueous solution of NaHCO₃

(1M, 5 mL) was added and the aqueous layer was extracted

with CH₂Cl₂(3 x 10 mL). The organic layers were combined

and dried over MgSO₄. The solvent was evaporated and the

residue was purified by TLC (CH₂Cl₂/EtOAc/MeOH :

7/2.5/0.5) to yield expected compound 20 as an oil (32 mg,

24 % yield). TLC (CH₂Cl₂/MeOH : 95/5) Rf = 0.8;

HPLC (TSK gel, 10 min) : tr = 5.0 min ; P_HPLC= 98 %;

HPLC (C4, 40 min) : tr = 12.6 min ; P_HPLC= 98 %; MALDI-

1

MALDI-TOF : 376.2 [M+H]⁺; H NMR 300 MHz (CDCl₃),

ꢀ(ppm) : 1.94 (quint, 2H, H_2’, J_2’-1’= J_2’-3’= 7Hz); 2.5-2.6 (m,

2

4H, H_3’et H_6’); 2.66 (dd, 1H, H_10ꢁ, J = 16Hz, J_10ꢁ-10a

=

2

12Hz); 2.8-2.9 (m, 2H, H_4’) ; 3.16 (dd, 1H, H_10ꢂ, J = 16Hz,

_10ꢂ-10a= 5Hz); 3.5-3.6 (m, 2H, H_5’); 3.6-3.7 (m, 2H, H_1’, J_1’-2’

= 7Hz); 3.94 (dd, 1H, H_10a, J_10a-10ꢁ= 12Hz, J_10a-10ꢂ= 5Hz);

J

2

4.30 (d, 1H, H₅, J = 17Hz) ; 4.98 (d, 1H, H₅, J = 17Hz) ;

7.0-7.3 (m, 8H, H_aro); ¹³C NMR 75 MHz (CDCl₃), ꢀ(ppm) :

25.1 (C_2’) ; 28.9 (C_6’) ; 30.5 (C₁₀) ; 37.4 (C_1’) ; 41.4 (C₅) ;

50.8 (C_4’) 54.4 (C_10a) ; 55.7 (C_5’); 55.9 (C_3’) ; 125.4-129.3

(C_aro).

1

TOF : 406.3 [M+H]⁺; H NMR 300 MHz (CDCl₃), ꢀ(ppm) :

0.89 (d, 6H, H_7’, J_7’-6’= 7Hz); 1.7-1.8 (m, 3H, H_6’et H_2’);

1.16 (d, 2H, H_5’,J_5’-6’= 7Hz); 2.39 (t, 2H, H_3’, J_3’-2’= 7Hz);

2.68 (dd, 1H, H_10ꢁ, ²J = 15Hz, J_10ꢁ-10a= 12Hz); 3.20 (dd, 1H,

H_10ꢂ, ²J = 15Hz, J_10ꢂ-10a= 5Hz); 3.50 (s, 2H, H_4’); 3.55 (t, 2H,

tert-butyl-3-(1-Benzylpiperidin-4-ylcarbamoyl)-3,4-dihydro-

1H-isoquinoline-2-carbamate 49

H_1’,J_1’-2’= 7Hz); 3.99 (dd, 1H, H_10a, J_10a-10ꢁ= 12Hz, J_10a-10ꢂ

=

2

5Hz); 4.38 (d, 1H, H₅, J = 17Hz); 4.99 (d, 1H, H₅, J =

17Hz) ; 7.1-7.3 (m, 9H, H_aro); ¹³C NMR 75 MHz (CDCl₃),

ꢀ(ppm) : 21.0 (C_7’); 25.8 (C_2’); 26.5 (C_6’) ; 31.0 (C₁₀) ; 37.4

(C_1’) ; 41.7 (C₅) ; 51.4 (C_3’) ; 54.7 (C_10a) ; 59.2 (C_4’) ; 62.7

(C_5’) ; 126.8-127.3-127.5-128.2-129.0-129.6 (C_aro).

To a solution of Boc-Tic-OH (5.20mmol, 1.44g) (see

synthesis of compound 40), in CH₂Cl₂(10 mL) were added

DIEA (3 eq, 2.7mL), HOBt (1.2 eq, 843 mg), HBTU (1.2 eq,

2.37g) and benzylpiperidine (5.20 mmol, 2.99 mL). The mix-

ture was stirred overnight at r.t.. The organic layer was

washed with an aqueous solution of NaHCO₃(5 %, 3x70

mL), a saturated solution of NaCl (1x70 mL) and dried over

MgSO₄. The solvent was evaporated. The residue was puri-

fied by TLC (CH₂Cl₂/MeOH : 95/5) to yield expected com-

pound 49 as a white solid (1.68 g, 72 % yield). TLC

(CH₂Cl₂/MeOH : 95/5) Rf = 0.5; HPLC (TSK gel, 10 min) :

tr = 2.2 min ; P_HPLC= 69 %; MALDI-TOF : 450.3 [M+H]⁺;

¹H NMR 300 MHz (CDCl₃), ꢀ(ppm) : 1.2-1.3 (m, 2H, H_2’);

1.46 (s, 9H, C(CH₃)₃); 1.7-1.8 (m, 2H, H_2’); 2.0-2.1 (m, 2H,

H_3’); 2.5-2.6 (m, 2H, H_3’); 3.0-3.2 (m, 2H, H₁₀); 3.40 (s, 2H,

H_4’); 3.6-3.7 (m, 2H, H_1’); 4.4-4.6 (m, 3H, H₅et H_10a); 7.2-

7.3 (m, 9H, H_aro); ¹³C NMR 75 MHz (CDCl₃), ꢀ(ppm) : 28.3

(C(CH₃)₃) ; 32.0 (C_2’) ; 32.3 (C₁₀) ; 44.5 (C₅) ; 45.8 (C_1’) ;

51.9 (C_3’) ; 56.9 (C_10a) ; 63.0 (C_4’) ; 126.1-127.0-127.8-

128.2-129.1 (C_aro).

2-[3-(1,3-dihydroisoindol-2-yl)propyl]-10,10a-dihydro-5H-

imidazo[1,5-b]isoquinoline-1,3-dione 21

To a solution of 37 (1.1 eq, 264 mg) in CH₂Cl₂(20 mL)

was added isoindoline (0.93 mmol, 0.176 mL) and the mix-

ture was stirred for 15 min at r.t.. NaBH(OAc)₃(5 eq, 985

mg) and glacial acetic acid (2 eq, 0.067 mL) were added and

the solution was stirred overnight at r.t.. The reaction was

quenched with an aqueous solution of NaHCO₃(30mL) fol-

lowed by extraction with CH₂Cl₂(3x30mL). The organic

layers were combined and dried over MgSO₄. The solvent

was evaporated and the residue was purified by TLC

(CH₂Cl₂/MeOH : 95/5) to yield expected compound 21 as a

white solid (67 mg, 20 % yield). TLC (AcOEt/MeOH : 92/8)

Rf = 0.6; HPLC (TSK gel, 10 min): tr = 4.4min; P_HPLC= 96

New Synthesis of Tic-Hydantoins Sigma-1 Ligands and Pharmacological Evaluation

Medicinal Chemistry, 2010, Vol. 6, No. 6 369

95/5) Rf = 0.3; HPLC (TSK gel, 10 min) : tr = 4.8 min ;

2-(1-benzylpiperidin-4-yl)-10,10a-dihydro-5H-imidazo[1,5-

b]isoquinoline-1,3-dione 23

P

_HPLC= 98 %; HPLC (C4, 40 min) : tr = 3.3 min ; P_HPLC= 99

1

%; ES-MS : 390.1 [M+H]⁺; H NMR 300 MHz (CDCl₃),

A solution of 49 (4.82 mmol, 2.17 g) in a mixture of

CH₂Cl₂/TFA (6/4 mL) was stirred for 1 h at r.t. The solvent

was evaporated. The crude was dissolved in THF (50 mL)

and DIEA (3 eq, 2.52mL) was added. After stirring for 10

min at r.t., CDI (3 eq, 2.35g) was added and the solution was

refluxed overnight. The solvent was evaporated and the

crude was dissolved in EtOAc (100 mL). The organic layer

was washed with an aqueous solution of NaHCO₃(5 %, 2x50

mL), a saturated solution of NaCl (1x50 mL) and dried over

MgSO₄. After evaporation, the residue was purified by flash

chromatography (EtOAc/cyclohexane : 3/7) to yield ex-

pected compound 23 as a white solid (1 g , 55 % yield). TLC

(CH₂Cl₂/MeOH : 98/2) Rf = 0.5; HPLC (TSK gel, 10 min) :

tr = 4.8 min ; P_HPLC= 98 %; HPLC (C4, 40 min) : tr =11.0

2

ꢀ(ppm) : 1.6-1.7 (m, 2H, H_2eq’, J = 12Hz); 2.19 (td, 2H,

H

_3ax’, ²J = J_{3ax’-2ax’}= 12Hz, J_{3ax’-2ex’}= 2Hz); 2.35 (s, 3H, CH₃);

2.59 (qd, 2H, H_2ax’, ²J = J_{2ax’-3ax’}= J_{2ax’-1ax’}= 12Hz, J_{2ax’-3eq’}

=

3Hz); 2.81 (dd, 1H, H_10ꢁ, ²J = 16Hz, J_10ꢁ-10a= 12Hz); 3.0-3.1

(m, 2H, H_3eq’, ²J = 12Hz); 3.26 (dd, 1H, H_10ꢂ, ²J = 15Hz, J_10ꢂ-

_10a= 5Hz); 3.50 (s, 2H, H_4’); 3.9-4.1 (m, 1H, H_1a’, J_{1ax’-2ax’}

=

12Hz); 4.01 (dd, 1H, H_10a,J_10a-10ꢁ= 12Hz, J_10a-10ꢂ= 5Hz);

5.01 (d, 1H, H₅, ²J = 16Hz); 7.1-7.3 (m, 2H, H_aro); ¹³C NMR

75 MHz (CDCl₃), ꢀ(ppm) : 24.1 (CH₃) ; 30.7 (C_2’) ; 33.8

(C₁₀) ; 44.6 (C₅) ; 52.4 (C_1’) ; 55.1 (C_3’) ; 57.1 (C_10a) ; 64.2

(C_4’) ; 129.6-130.2-130.3-132.0-132.4-132.5 (C_aro).

2-[1-(4-tert-butylbenzyl)piperidin-4-yl]-10,10a-dihydro-5H-

imidazo[1,5-b]isoquinoline-1,3-dione 25

1

min ; P_HPLC= 99 % ES-MS : 376.2 [M+H]⁺; H NMR 300

A solution of amine 50 (0.18 mmol, 53 mg) and 4-tert-

butylbenzaldehyde (1.5 eq, 0.046 mL) in CH₂Cl₂(2 mL) was

stirred for 15 min at r.t.. NaBH(OAc)₃(1.5 eq, 59 mg) was

added and the solution was stirred overnight at r.t.. The sol-

vent was evaporated and the residue was purified by TLC

(CH₂Cl₂/EtOAc/MeOH : 6/3.5/0.5) to yield expected com-

pound 25 as a yellow solid (23 mg, 28 % yield). TLC

(CH₂Cl₂/AcOEt/MeOH : 6/3,5/0,5) Rf = 0.3; HPLC (TSK

gel, 10 min) : tr = 6.0 min ; P_HPLC= 97 %; HPLC (C4, 40

min) : tr = 13.5 min ; P_HPLC= 98 %; ES-MS : 432.2 [M+H]⁺;

¹H NMR 300 MHz (CDCl₃), ꢀ(ppm) : 1.25 (s, 9H, C(CH₃)₃);

MHz (CDCl₃), ꢀ(ppm) : 1.6-1.7 (m, 2H, H_2eq’); 2.06 (td, 2H,

2

H_3ax’, J = J_{3ax’-2ax’}= 12Hz, J_{3ax’-2eq’}= 2Hz); 2.50 (qd, 2H,

2

H_2ax’, J = J_{2ax’-3ax’}= J_{2ax’-1ax’}= 12Hz, J_{2ax’-3eq’}= 3Hz); 2.81

2

(dd, 1H, H_10ꢁ, J = 16Hz, J_10ꢁ-10a= 12Hz); 2.9-3.0 (m, 2H,

2

H

_3eq’, J = 12Hz); 3.24 (dd, 1H, H_10ꢂ, J = 15Hz, J_10ꢂ-10a

=

5Hz); 3.52 (s, 2H, H_4’); 3.9-4.0 (m, 2H, H_1’et H_10a,J_10a-10ꢁ

2

12Hz, J_10a-10ꢂ= 5Hz); 4.39 (d, 1H, H₅, J = 16Hz); 4.99 (d,

1H, H₅, ²J = 16Hz); 7.2-7.4 (m, 9H, H_aro); ¹³C NMR 75 MHz

(CDCl₃), ꢀ(ppm) : 31.1 (C_2’) ; 33.4 (C₁₀) ; 44.1 (C₅) ; 52.6

(C_1’) ; 55.4 (C_3’) ; 56.7 (C_10a) ; 65.2 (C_4’) ; 129.1-129.4-

129.7-129.8-130.7-131.5-131.9(C_aro).

2

1.5-1.6 (m, 2H, H_2eq’,²J = 12Hz); 2.0-2.1 (m, 2H, H_3ax’, J =

2-piperidin-4-yl-10,10a-dihydro-5H-imidazo[1,5-b]isoquino-

line-1,3-dione 50

J_{3ax’-2ax’}= 12Hz); 2.45 (qd, 2H, H_2ax’, ²J = J_{2ax’-3ax’}= J_{2ax’-1ax’}

=

2

12Hz, J_{2ax’-3eq’}= 4Hz); 2.73 (dd, 1H, H_10ꢁ, J = 16Hz, J_10ꢁ-10a

2

= 12Hz); 2.9-3.0 (m, 2H, H_3eq’, J = 12Hz); 3.19 (dd, 1H,

To a solution of 23 (2.64 mmol, 990 mg) in MeOH (10

mL), was added Pd/C (10 %, 0.3 eq, 84 mg) and ammonium

formate (3 eq, 499 mg). The mixture was reflux for 5 h and

then filtered through celite. The solvent was evaporated and

the residue was purified by flash chromatography

(CH₂Cl₂/MeOH: 9/1) to yield expected compound 50 as a

white solid (746 mg, 99 % yield). TLC (CH₂Cl₂/MeOH: 8/2)

Rf = 0.2; HPLC (TSK gel, 10 min) : tr = 3.7 min ; P_HPLC= 90

H

_10ꢂ, ²J = 15Hz, J_10ꢂ-10a= 5Hz); 3.43 (s, 2H, H_4’); 3.9-4.0 (m,

1H, H_1ax’, J_{1ax’-2ax’}= 12Hz); 3.94 (dd, 1H, H_10a,J_10a-10ꢁ

=

2

12Hz, J_10a-10ꢂ= 5Hz); 4.32 (d, 1H, H₅, J = 16Hz); 4.94 (d,

1H, H₅, ²J = 16Hz); 7.1-7.3 (m, 8H, H_aro); ¹³C NMR 75 MHz

(CDCl₃), ꢀ(ppm) : 31.0 (C_2’) ; 33.3 (C₁₀) ; 33.7 (CH₃) ; 43.9

(C₅) ; 52.5 (C_1’) ; 55.3 (C_3’) ; 56.5 (C_10a) ; 64.7 (C_4’) ; 127.4-

129.0-129.5-129.7-131.1-131.8 (C_aro).

1

%; ES-MS : 286,19 [M+H]⁺; H NMR 300 MHz (CDCl₃),

2-[1-(4-methoxybenzyl)piperidin-4-yl]-10,10a-dihydro-5H-

imidazo[1,5-b]isoquinoline-1,3-dione 26

2

ꢀ(ppm) 1.6-1.7 (m, 2H, H_2eq’); 2.2-2.3 (m, 2H, H_2ax’, J =

J_{2ax’-3ax’}= J_{2ax’-1ax’}= 12Hz 12Hz, J_{2ax’-3eq’}= 2Hz); 2.62 (td,

2H, H_3ax’, ²J = J_{3ax’-2ax’}= 12Hz, J_{3ax’-2eq’}= 2Hz); 2.75 (dd, 1H,

H_10ꢁ, ²J = 16Hz, J_10ꢁ-10a= 12Hz); 3.1-3.2 (m, 2H, H_3eq’); 3.18

A solution of amine 50 (0.16 mmol, 46 mg) and 4-

methoxybenzaldehyde (1.5 eq, 0.03 mL) in CH₂Cl₂(2 mL)

was stirred for 15 min at r.t.. NaBH(OAc)₃(1.5 eq, 51 mg)

was added and the solution was stirred overnight at r.t.. The

solvent was evaporated and the residue was purified by TLC

(CH₂Cl₂/EtOAc/MeOH : 6/3.5/0.5) to yield expected com-

pound 26 as white solid (22 mg, 34 % yield). TLC

(CH₂Cl₂/AcOEt/MeOH : 6/3,5/0,5) Rf = 0.3; HPLC (TSK

gel, 10 min) : tr = 4.9 min ; P_HPLC= 98 %; HPLC (C4, 40

min) : tr = 3.7 min ; P_HPLC= 99 %; ES-MS : 406.2 [M+H]⁺;

¹H NMR 300 MHz (CDCl₃), ꢀ(ppm) : 1.5-1.6 (m, 2H, H_2eq’);

1.97 (td, 2H, H_3a’, ²J = J_{3ax’-2ax’}= 12Hz, J_{3ax’-2eq’}= 2Hz); 2.44

(qd, 2H, H_2ax’, ²J = J_{2ax’-3ax’}= J_{2ax’-1ax’}= 12Hz, ²J = 3Hz); 2.73

2

(dd, 1H, H_10ꢂ, J = 15Hz, J_10ꢂ-10a= 5Hz); 3.96 (dd, 1H, H_10a,

J_10a-10ꢁ= 12Hz, J_10a-10ꢂ= 5Hz); 3.1-4.1 (m, 1H, H_1a’, J_{1ax’-2ax’}

=

2

12Hz); 4.34 (d, 1H, H₅, J = 17Hz); 4.95 (d, 1H, H₅, J =

17Hz); 7.1-7.2 (m, 9H, H_aro); ¹³C NMR 75 MHz (CDCl₃),

ꢀ(ppm) : 29.90 (C_2’) ; 30.9 (C₁₀) ; 41.6 (C₅) ; 46.0 (C_3’) ; 49.7

(C_1’) ; 54.1 (C_10a) ; 126.6-127.2-127.3-129.4(C_aro).

2-[1-(4-methylbenzyl)piperidin-4-yl]-10,10a-dihydro-5H-imi-

dazo[1,5-b]isoquinoline-1,3-dione 24

A solution of amine 50 (0.84 mmol, 240 mg) and p-

tolualdehyde (1.5 eq, 0.15 mL) in CH₂Cl₂(5 mL) was stirred

for 15 min at r.t.. NaBH(OAc)₃(1.5 eq, 268 mg) was added

and the solution was stirred overnight at r.t.. The solvent was

evaporated and the residue was purified by TLC

(CH₂Cl₂/MeOH : 95/5) to yield expected compound 24 as a

white solid (121 mg, 37 % yield). TLC (CH₂Cl₂/MeOH :

2

(dd, 1H, H_10ꢁ, J = 16Hz, J_10ꢁ-10a= 12Hz); 2.9-3.0 (m, 2H,

2

H_3eq’, J = 12Hz); 3.18 (dd, 1H, H_10ꢂ, J = 15Hz, J_10ꢂ-10a

=

5Hz); 3.39 (s, 2H, H_4’); 3.73 (s, 3H, OCH₃); 3.8-4.0 (m, 1H,

H_1ax’, J_{1ax’-2ax’}= 12Hz); 3.93 (dd, 1H, H_10a,J_10a-10ꢁ= 12Hz,

2

J_10a-10ꢂ= 5Hz); 4.31 (d, 1H, H₅, J = 16Hz); 4.93 (d, 1H, H₅,

²J = 16Hz); 6.7-6.8 (m, 2H, H_6’J_6’-5’= 9Hz, J_6’-6’= 3Hz) ; 7.1-

370 Medicinal Chemistry, 2010, Vol. 6, No. 6

Toussaint et al.

7.2 (m, 6H, H_5’, H_9’, H₆, H₇, H₈et H₉); ¹³C NMR 75 MHz

(CDCl₃), ꢀ(ppm): 31.0 (C_2’); 33.5 (C₁₀); 44.1 (C₅); 52.6 (C_1’) ;

55.3 (C_3’); 56.7 (C_10a); 57.8 (OCH₃); 64.4(C_4’); 116.1(C_6’);

129.2-129.7-129.8-131.9-132.7(C_5’, C_9’, C₆, C₇, C₈et C₉).

was stirred for 15 min at r.t.. NaBH(OAc)₃(1.5 eq, 174 mg)

was added and the solution was stirred overnight at r.t.. The

solvent was evaporated and the residue was purified by TLC

(CH₂Cl₂/MeOH : 95/5) to yield expected compound 29 as a

white solid (122 mg, 58 % yield). TLC (CH₂Cl₂/MeOH :

96/4) Rf = 0.3; HPLC (TSK gel, 10 min) : tr = 4.9 min ;

2-[1-(4-nitrobenzyl)piperidin-4-yl]-10,10a-dihydro-5H-imid-

azo[1,5-b]isoquinoline-1,3-dione 27

P_HPLC= 99 %; HPLC (C4, 40 min) : tr = 11.4 min ; P_HPLC

=

1

99 %; ES-MS : 382.2 [M+H]⁺; H NMR 300 MHz (CDCl₃),

A solution of amine 50 (0.81 mmol, 231 mg) and 4-

nitrobenzaldehyde (1.5 eq, 183 mg) in CH₂Cl₂(2 mL) was

stirred for 15 min at r.t.. NaBH(OAc)₃(1.5 eq, 258 mg) was

added and the solution was stirred overnight at r.t.. The sol-

vent was evaporated and the residue was purified by TLC

(CH₂Cl₂/MeOH : 98/2) to yield expected compound 27 as a

yellow solid (364 mg, 94 % yield). TLC (CH₂Cl₂/MeOH :

95/5) Rf = 0.5; HPLC (TSK gel, 10 min) : tr = 4.7 min ;

2

ꢀ(ppm) : 0.8-0.9 (m, 2H, H_7’, J = J_7’-6’= J_7’-8’= 12Hz); 1.0-

1.1 (m, 3H, H_6’et H_8’); 1.4-1.5 (m, 1H, H_5’); 1.5-1.9 (m, 7H,

H

_2eq’, H_6’, H_7’et H_8’); 2.0-2.1 (m, 2H, H_3ax’); 2.16 (d, 2H, H_4’,

2

J_4’-5’= 7Hz); 2.4-2.6 (qd, 2H, H_2ax’, J = J₂₂_ax’-1ax’= J_{2ax’-3ax’}

=

12Hz, J_{2ax’-3eq’}= 4Hz); 2.72 (dd, 1H, H_10ꢁ, J = 16Hz, J_10ꢁ-10a

2

= 12Hz); 2.9-3.1 (m, 2H, H_3eq’, J = 12Hz); 3.19 (dd, 1H,

H_10ꢂ, ²J = 15Hz, J_10ꢂ-10a= 5Hz); 3.8-4.0 (m, 1H, H_1ax’, J_{1ax’-2ax’}

= 12Hz); 3.96 (dd, 1H, H_10a,J_10a-10ꢁ= 12Hz, J₁₀₂_a-10ꢂ= 5Hz);

P

_HPLC= 98 %; HPLC (C4, 40 min) : tr = 10.2 min ; P_HPLC=

2

1

98 %; ES-MS : 421.2 [M+H]⁺; H NMR 300 MHz (CDCl₃),

4.33 (d, 1H, H₅, J = 16Hz); 4.94 (d, 1H, H₅, J = 16Hz) ;

7.1-7.2 (m, 4H, H_aro); ¹³C NMR 75 MHz (CDCl₃), ꢀ(ppm) :

29.1 (C_6’) ; 29.7 (C_8’) ; 30.9 (C_2’) ; 33.9 (C₁₀) ; 34.8 (C_7’) ;

38.1 (C_5’) ; 44.6 (C_5’) ; 52.8 (C_1’); 56.2 (C_3’) ; 57.2 (C_10a) ;

67.5 (C_4’) ; 129.6-130.2-130.3-132.4 (C_aro).

ꢀ(ppm) : 1.6-1.7 (m, 2H, H_2eq’,²J = 12Hz); 2.14 (td, 2H,

H_3ax’, J_{3ax’-2ax’}= ²J = 12Hz, J_{3ax’-2eq’}=3Hz); 2.55 (qd, 2H, H_2ax’

,

²J = J_{2ax’-3ax’}= J_{2ax’-1ax’}= 12Hz, J_{2ax’-3eq’}= 3Hz); 2.81 (dd, 1H,

2

H

_10ꢁ, J = 16Hz, J_10ꢁ-10a= 12Hz); 2.9-3.0 (m, 2H, H_3eq’, J =

12Hz); 3.26 (dd, 1H, H_10ꢂ, ²J = 15Hz, J_10ꢂ-10a= 5Hz); 3.62 (s,

2H, H_4’); 3,9-4,0 (m, 1H, H_1ax’, J_{1ax’-2ax’}= 12Hz); 4.03 (dd,

1H, H_10a,J_10a-10ꢁ= 12Hz, J_10a-10ꢂ= 5Hz); 4.39 (d, 1H, H₅, ²J =

2-[3-(4-phenylpiperazin-1-yl)propyl]-10,10a-dihydro-5H-imi-

dazo[1,5-b]isoquinoline-1,3-dione 30

2

16Hz); 5.00 (d, 1H, H₅, J = 16Hz); 7.2-7.3 (m, 4H, H₆, H₇,

To a solution of 37 (1.1 eq, 0.48 mmol) in CH₂Cl₂(15

mL) was added phenylpiperazine (0.44 mmol, 0.067 mL)

and the mixture was stirred for 15 min at r.t.. NaBH(OAc)₃

(5 eq, 465 mg) and glacial acetic acid (1 eq, 0,025 mL) were

added and the solution was stirred overnight at r.t. The reac-

tion was quenched with an aqueous solution of NaHCO₃

(30mL) followed by extraction with CH₂Cl₂(3x30mL). The

organic layers were combined and dried over MgSO₄. The

solvent was evaporated and the residue was purified by TLC

(CH₂Cl₂/MeOH : 95/5) to yield expected compound 30 as an

orange oil (85 mg, 44 % yield). TLC (CH₂Cl₂/MeOH : 95/5)

Rf = 0.4; HPLC (TSK gel, 10 min) : tr = 4.9 min ; P_HPLC= 95

%; HPLC (C4, 40 min) : tr = 11.1 min ; P_HPLC= 99 %; ES-

H₈et H₉) ; 7.5-7.6 (d, 2H, H_6’, J_6’-5’= 9Hz) ; 8.1-8.2 (m, 2H,

H_5’, J_5’-6’= 9Hz, J_5’-5’= 2Hz); ¹³C NMR 75 MHz (CDCl₃),

ꢀ(ppm) : 31.4 (C_2’) ; 33.9 (C₁₀) ; 44.6 (C₅) ; 52.6 (C_1’) ; 56.0

(C_3’) ; 57.2 (C_10a) ; 64.6 (C_4’) ; 126.5 (C_6’); 129.6-130.2-

130.3 (C₆, C₇, C₈et C₉) 132.4 (C_5’).

2-[1-(4-fluorobenzyl)piperidin-4-yl]-10,10a-dihydro-5H-imi-

dazo[1,5-b]isoquinoline-1,3-dione 28

A solution of amine 50 (0.23 mmol, 66 mg) and 4-

fluorobenzaldehyde (1.5 eq, 0.036 mL) in CH₂Cl₂(5 mL)

was stirred for 15 min at r.t.. NaBH(OAc)₃(1.5 eq, 72 mg)

was added and the solution was stirred overnight at r.t.. The

solvent was evaporated and the residue was purified by TLC

(CH₂Cl₂/MeOH : 95/5) to yield expected compound 28 as a

white solid (53 mg, 59 % yield). TLC (CH₂Cl₂/MeOH :

96/4) Rf = 0.6; HPLC (TSK gel, 10 min) : tr = 4.7 min ;

1

MS : 405.2[M+H]⁺; H NMR 300 MHz (CDCl₃), ꢀ(ppm) :

1.88 (quint, 2H, H_2’, J_2’-3’= J_2’-1’= 7Hz); 2.47 (t, 2H, H_3’, J_3’-

= 7Hz); 2.5-2.6 (m, 4H, H_4’, J_4’-5’= 5Hz); 2.84 (dd, 1H,

2’

H_10ꢁ, ²J = 15Hz, J_10ꢁ-10a= 12Hz,); 3.1-3.2 (m, 4H, H_5’, J_5’-4’

=

2

5Hz); 3.27 (dd, 1H, H_10ꢂ, J = 15Hz, J_10ꢂ-10a= 5Hz); 3.65 (t,

2H, H_1’, J_3’-2’= 7Hz); 4.06 (dd, 1H, H_10a,J_10a-10ꢁ= 12Hz, J_10a-

_10ꢂ= 5Hz); 4.41 (d, 1H, H₅, ²J = 17Hz); 5.02 (d, 1H, H₅, ²J =

17Hz); 6.84 (td, 1H, H_8’,J_8’-7’= 7Hz, J_8’-6’= 1Hz) ; 6.90 (td,

2H, H_6’,J_6’-7’= 7Hz, J_6’-8’= J_6’-6’= 1Hz) ; 7.2-7.3 (m, 6H, H_7’,

H₆, H₇, H₈et H₉) ¹³C NMR 75 MHz (CDCl₃), ꢀ(ppm) : 27.7

(C_2’) ; 33.3 (C₁₀) ; 39.7 (C_1’) ; 44.0 (C₅) ; 51.5 (C_5’) ; 55.5

(C_4’) ; 57.0 (C_10a) ; 58.2 (C_3’) ; 118.3 (C_6’); 122.0 (C_8’);

129.0-129.6-129.7-131.4-131.8 (C_aro).

P_HPLC= 99 %; HPLC (C4, 40 min) : tr = 21.8 min ; P_HPLC

=

1

96 %; MALDI-TOF : 394.1 [M+H]⁺; H NMR 300 MHz

(CDCl₃), ꢀ(ppm) : 1.6-1.7 (m, 2H, H_2eq’); 2.04 (td, 2H, H_3ax’

,

²J = J_{3ax’-2ax’}= 12Hz, J_{3ax’-2eq’}= 2Hz); 2.51 (qd, 2H, H_2ax’, ²J =

J_{2ax’-3ax’}= J_{2ax’-1ax’}= 12Hz, J_{2ax’-3eq’}= 3Hz); 2.81 (dd, 1H, H_10ꢁ,

²J = 16Hz, J_10ꢁ-10a= 12Hz); 2.9-3.0 (m, 2H, H_3eq’, ²J = 12Hz);

2

3.26 (dd, 1H, H_10ꢂ, J = 15Hz, J_10ꢂ-10a= 5Hz); 3.48 (s, 2H,

H_4’); 3.9-3.4 (m, 1H, H_1ax’, J_{1ax’-2ax’}= 12Hz); 4.01 (dd, 1H,

2

H_10a,J_10a-10ꢂ= 5Hz, J_10a-10ꢁ= 12Hz); 4.39 (d, 1H, H₅, J =

16Hz); 5.00 (d, 1H, H₅, ²J = 16Hz); 6.9-7.1 (m, 2H, H_6’J_6’-5’

= 9Hz, J_6’-6’= 2Hz) ; 7.2-7.4 (m, 6H, H_5’, H_9’, H₆, H₇, H₈et

H₉); ¹³C NMR 75 MHz (CDCl₃), ꢀ(ppm) : 30.8 (C_2’) ; 33.3

(C₁₀) ; 43.9 (C₅) ; 52.3 (C_1’) ; 55.3 (C_3’) ; 56.6 (C_10a) ; 64.2

(C_4’) ; 117.2 (C_6’); 129.0-129.6-129.7-131.8-132.7-132.8

(C_5’, C_9’, C₆, C₇, C₈et C₉).

2-[3-(4-p-tolylpiperazin-1-yl)propyl]-10,10a-dihydro-5H-imi-

dazo[1,5-b]isoquinoline-1,3-dione 31

To a solution of 37 (1.1 eq, 0.48 mmol) in CH₂Cl₂(15

mL) was added 1-(4-methylphenyl)piperazine (0.44 mmol,

77 mg) and the mixture was stirred for 15 min at r.t.

NaBH(OAc)₃(5 eq, 462 mg) and glacial acetic acid (1 eq,

0,025 mL) were added and the solution was stirred overnight

at r.t. The reaction was quenched with an aqueous solution of

NaHCO₃(30mL) followed by extraction with CH₂Cl₂

(3x30mL). The organic layers were combined and dried over

2-(1-(cyclohexylmethyl)piperidin-4-yl)-10,10a-dihydro-5H-

imidazo[1,5-b]isoquinoline-1,3-dione 29

A solution of amine 50 (0.55 mmol, 157 mg) and cyclo-

hexanecarboxaldehyde (1.5 eq, 0.1 mL) in CH₂Cl₂(5 mL)

New Synthesis of Tic-Hydantoins Sigma-1 Ligands and Pharmacological Evaluation

Medicinal Chemistry, 2010, Vol. 6, No. 6 371

MgSO₄. The solvent was evaporated and the residue was

purified by TLC (CH₂Cl₂/MeOH : 95/5) to yield expected

compound 31 as a yellow solid (110 mg, 60 % yield). TLC

(CH₂Cl₂/MeOH : 95/5) Rf = 0.4; HPLC (TSK gel, 10 min) :

tr = 5.1 min ; P_HPLC= 98 %; HPLC (C4, 40 min) : tr = 11.1

purified by TLC (CH₂Cl₂/MeOH : 95/5) to yield expected

compound 33 as a yellow oil (29 mg, 20 % yield). TLC

(CH₂Cl₂/MeOH : 95/5) Rf = 0.4; HPLC (TSK gel, 10 min) :

tr = 4.9 min ; P_HPLC= 99 %; HPLC (C4, 40 min) : tr = 22.4

1

min ; P_HPLC= 95 %; ES-MS: 423.2 [M+H]⁺; H NMR 300

1

min ; P_HPLC= 96 %; ES-MS: 19.2 [M+H]⁺; H NMR 300

MHz (CDCl₃), ꢀ(ppm) : 1.83 (quint, 2H, H_2’, J_2’-3’= J_2’-1’=

MHz (CDCl₃), ꢀ(ppm) : 1.88 (quint, 2H, H_2’, J_2’-3’= J_2’-1’

=

7Hz); 2.42 (t, 2H, H_3’, J_3’-2’= 7Hz); 2.5-2.6 (m, 4H, H_4’, J_4’-5’

7Hz); 2.25 (s, 3H, H_8’); 2.47 (t, 2H, H_3’, J_3’-2’= 7Hz); 2.5-2.6

(m, 4H, H_4’, J_4’-5’= 5Hz); 2.84 (dd, 1H, H_10ꢁ, ²J = 15Hz, J_10ꢁ-

_10a= 12Hz,); 3.1-3.2 (m, 4H, H_5’, J_5’-4’= 5Hz); 3.27 (dd, 1H,

= 5Hz); 2.78 (dd, 1H, H_10ꢁ, ²J = 15Hz, J_10ꢁ-10a= 12Hz,); 3.0-

2

3.1 (m, 4H, H_5’, J_5’-4’= 5Hz); 3.20 (dd, 1H, H_10ꢂ, J = 15Hz,

J_10ꢂ-10a= 5Hz); 3.59 (t, 2H, H_1’, J_3’-2’= 7Hz); 4.03 (dd, 1H,

2

H

_10ꢂ, ²J = 15Hz, J_10ꢂ-10a= 5Hz); 3.65 (t, 2H, H_1’, J_3’-2’= 7Hz);

H_10a,J_10a-10ꢁ= 12Hz, J_10a-10ꢂ= 5Hz); 4.43 (d, 1H, H₅, J =

2

4.06 (dd, 1H, H_10a,J_10a-10ꢁ= 12Hz, J_10a-10ꢂ= 5Hz); 4.41 (d,

17Hz); 4.97 (d, 1H, H₅, J = 17Hz); 6.7-6.9 (m, 4H, H_7’et

2

1H, H₅, J = 17Hz); 5.02 (d, 1H, H₅, J = 17Hz); 6.82 (dt,

H_6’) ; 7.1-7.2 (m, 4H, H₆, H₇, H₈et H₉); ¹³C NMR 75 MHz

(CDCl₃), ꢀ(ppm) : 27.7 (C_2’) ; 33.3 (C₁₀) ; 39.7 (C_1’) ; 44.0

(C₅) ; 51.5 (C_5’) ; 55.5 (C_4’) ; 57.0 (C_10a) ; 58.2 (C_3’) ; 118.3

(C_6’); 122.0 (C_8’); 129.0-129.6-129.7-131.4-131.8 (C_aro).

2H, H_8’,J_7’-6’= 9Hz, J_7’-7’= 2Hz) ; 6.90 (dt, 2H, H_6’,J_6’-7’

=

9Hz, J_6’-6’= 2Hz) ; 7.2-7.3 (m, 4H, H₆, H₇, H₈et H₉); ¹³C

NMR 75 MHz (CDCl₃), ꢀ(ppm) : 20.7 (C_8’); 25.6 (C_2’) ; 31.2

(C₁₀) ; 37.6 (C_1’) ; 41.9 (C₅) ; 50.1 (C_5’) ; 53.5 (C_4’) ; 55.0

(C_10a) ; 56.1 (C_3’) ; 118.3 (C_6’); 116.7 (C_6’); 126.9-127.6-

127.7-129.8-129.9 (C_aro).

5.2. Binding Assays to Receptors

The binding assays were performed by CEREP (Paris,

France), according to Ganapathy et al. [37] for ꢃ₁binding

and Bowen et al. [38] for ꢃ₂binding. In brief, the ꢃ₁binding

assay was performed by incubating Jurkat cell membranes

(10–20 mg protein per tube) with [³H](+)-pentazocine (8

nM) and a range of concentrations of test compounds, at 22

°C for 2 h, in 5 mM Tris/HCl buffer, pHꢄ 7.4. The ꢃ₂bind-

ing assay was performed by incubating rat cerebral cortex

membranes (10–20 mg protein per tube) with [³H] (+)-

DTG(5 nM), in the presence of (+)-pentazocine (300 nM) to

saturate ꢃ₁sites, and a range of concentrations of test com-

pounds, at 22 °C for 2 h, in 5 mM Tris/HCl buffer, pH ꢄ 7.4.

The final assay volume was 0.5 mL. Non-specific binding

was defined, in both assays, as that remaining in the presence

of 10 mM haloperidol. The reaction was terminated by rapid

filtration through Whatman GF/B filters, which were then

washed with 5 x1 mL ice-cold 0.9 % NaCl (saline) solution

and allowed to dry before bound radioactivity was measured

using liquid scintillation counting. The protein concentration

in the homogenates was determined using the method of

Bradford [30].

2-{3-[4-(4-methoxyphenyl)piperazin-1-yl]propyl}-10,10a-di-

hydro-5H-imidazo[1,5-b]isoquinoline-1,3-dione 32

To a solution of 37 (1.1 eq, 0.39 mmol) in CH₂Cl₂(15

mL) was added 1-(4-methoxyphenyl)piperazine (0.36 mmol,

69 mg) and the mixture was stirred for 15 min at r.t..

NaBH(OAc)₃(5 eq, 383 mg) and glacial acetic acid (1 eq,

0,021 mL) were added and the solution was stirred overnight

at r.t.. The reaction was quenched with an aqueous solution

of NaHCO₃(30mL) followed by extraction with CH₂Cl₂

(3x30mL). The organic layers were combined and dried over

MgSO₄. The solvent was evaporated and the residue was

purified by TLC (CH₂Cl₂/MeOH : 95/5) to yield expected

compound 32 as an orange solid (8 mg, 5 % yield). TLC

(CH₂Cl₂/MeOH : 95/5) Rf = 0.4; HPLC (TSK gel, 10 min) :

tr = 4.8 min ; P_HPLC= 99 %; HPLC (C4, 40 min) : tr = 21.9

1

min ; P_HPLC= 99 %; ES-MS : 435.2 [M+H]⁺; H NMR 300

MHz (CDCl₃), ꢀ(ppm) : 1.83 (quint, 2H, H_2’, J_2’-3’= J_2’-1’

=

7Hz); 2.43 (t, 2H, H_3’, J_3’-2’= 7Hz); 2.5-2.6 (m, 4H, H_4’, J_4’-5’

= 5Hz); 2.78 (dd, 1H, H_10ꢁ, ²J = 15Hz, J_10ꢁ-10a= 12Hz,); 3.0-

2

3.1 (m, 4H, H_5’, J_5’-4’= 5Hz); 3.22 (dd, 1H, H_10ꢂ, J = 15Hz,

J_10ꢂ-10a= 5Hz); 3.59 (t, 2H, H_1’, J_3’-2’= 7Hz); 3.69 (s, 3H,

OMe); 4.02 (dd, 1H, H_10a,J_10a-10ꢁ= 12Hz, J_10a-10ꢂ= 5Hz); 4.36

5.3. Behavioral Pharmacology

2

(d, 1H, H₅, J = 17Hz); 4.97 (d, 1H, H₅, J = 17Hz); 6.7-6.8

(m, 4H, H_6’et H_7’, J_7’-6’= J_6’-7’= 9Hz, J_7’-7’= J_6’-6’= 2Hz) ;

7.1-7.2 (m, 6H, H₆, H₇, H₈et H₉); ¹³C NMR 75 MHz

(CDCl₃), ꢀ(ppm) : 25.2 (C_2’) ; 30.9 (C₁₀) ; 37.2 (C_1’) ; 41.6

(C₅) ; 50.5 (C_5’) ; 53.2 (C_4’) ; 54.7 (C_10a) ; 55.5 (C_OMe): 55.6

(C_3’) ; 114.4-118.2 (C_6’et C_7’); 126.7-127.2-127.4-129.4

(C_aro).

5.3.1. Animals

Male Swiss mice, 6–8 weeks old and weighing 28–32 g,

were purchased from Depré (St-Doulchard, France). Animals

were housed in groups of 10 with access to food and water

ad libitum, except during behavioral experiments. They were

kept in a temperature and humidity controlled animal facility

on a 12 h/12 h light/dark cycle (light on at 7:00 h). Experi-

ments were carried out between 9:00 h and 18:00 h, in a

sound-attenuated and air-regulated experimental room, to

which mice were habituated at least 30 min before each ex-

periment. All animal procedures were conducted in strict

adherence to the European Communities Council Directive

of 24 November 1986 (86-609/EEC).

2-{3-[4-(4-fluorophenyl)

piperazin-1-yl]propyl}-10,10a-

dihydro-5H-imidazo[1,5-b]isoquinoline-1,3-dione 33

To a solution of 37 (1.1 eq, 0.38 mmol) in CH₂Cl₂(16

mL) was added 1-(4-fluorophenyl)piperazine (0.34 mmol, 62

mg) and the mixture was stirred for 15 min at r.t..

NaBH(OAc)₃(5 eq, 366 mg) and glacial acetic acid (1 eq,

0,021 mL) were added and the solution was stirred overnight

at r.t.. The reaction was quenched with an aqueous solution

of NaHCO₃(30mL) followed by extraction with CH₂Cl₂

(3x30mL). The organic layers were combined and dried over

MgSO₄. The solvent was evaporated and the residue was

5.3.2. Drugs

Cocaine was from Cooper (Melun, France). The drug

was injected intraperitoneally (i.p.) in a volume of 100 μL

per 20 g b.w.

372 Medicinal Chemistry, 2010, Vol. 6, No. 6

Toussaint et al.

[15]

McCracken, K.A.; Bowen, W.D.; de Costa, B.R.; Matsumoto, R.R.

Two novel sigma receptor ligands, BD1047 and LR172, attenuate

cocaine-induced toxicity and locomotor activity. Eur. J. Pharma-

col., 1999, 370, 225-232.

McCracken, K.A.; Bowen, W.D.; Matsumoto, R.R. Novel sigma

receptor ligands attenuate the locomotor stimulatory effects of co-

caine. Eur. J. Pharmacol., 1999, 365, 35-38.

Menkel, M.; Terry, P.; Pontecorvo, M.; Katz, J.L.; Witkin, J.M.

Selective sigma ligands block stimulant effects of cocaine. Eur. J.

Pharmacol., 1991, 201, 251-252.

Romieu, P.; Martin-Fardon, R.; Maurice, T. Involvement of the

sigma1 receptor in the cocaine-induced conditioned place prefer-

ence. Neuroreport, 2000, 11, 2885-2888.

Romieu, P.; Phan, V.L.; Martin-Fardon, R.; Maurice, T. Involve-

ment of the sigma₁receptor in cocaine-induced conditioned place

preference: possible dependence on dopamine uptake blockade.

Neuropsychopharmacology. 2002, 26, 444-455.

Booth, RG.; Baldessarini, R.J. (+)-6,7-benzomorphan sigma

ligands stimulate dopamine synthesis in rat corpus striatum tissue.

Brain Res., 1991, 557, 349-352.

Kobayashi, T.; Matsuno, K.; Murai, M.; Mita, S. Sigma 1 receptor

subtype is involved in the facilitation of cortical dopaminergic

transmission in the rat brain. Neurochem. Res., 1997, 9, 1105-1109.

Bermack, J.E.; Debonnel, G. Modulation of serotonergic neuro-

transmission by short- and long-term treatments with sigma

ligands. Br. J. Pharmacol., 2001, 134, 691-699.

Campbell, B.G.; Scherz, M.W.; Keana, J.F.; Weber, E. Sigma

receptors regulate contractions of the guinea pig ileum longitudinal

muscle/myenteric plexus preparation elicited by both electrical

stimulation and exogenous serotonin. J. Neurosci., 1989, 9, 3380-

3391.

5.3.3. Locomotor Activity

Animals were injected with saline vehicle solution, co-

caine (10 mg/kg i.p.) and/or compounds 19, 21, 22 (1 mg/kg

i.p., 10 min before cocaine). After injection, mice were

placed in a 40 ꢀ 40 ꢀ 15 cm cage for 40 min. Locomotion

was recorded using infra-red beams counting (Columbus

Inst., Columbus, OH, USA) and measured over 30 min, be-

tween 10 and 40 min. data were analyzed using a one-way

ANOVA, followed by a Dunnett's post-hoc comparison test.

[16]

[17]

[18]

[19]

ACKNOWLEDGMENTS

We express our thanks to Gérard Montagne for NMR

experiments and Hervé Drobecq for MS spectra. This work

was supported by Université de Lille II and MILDT (Paris,

France). M.T. was a recipient of fellowships from the Région

Nord-Pas de Calais and CNRS.

[20]

[21]

[22]

[23]

REFERENCES

[1]

Carroll, F.I.; Howell, L.L.; Kuhar, M.J. Pharmacotherapies for

treatment of cocaine abuse: preclinical aspects. J. Med. Chem.,

1999, 42, 2721-2736.

[2]

[3]

Koob, G.F., Nestler, E.J. The neurobiology of drug addiction. J.

Neuropsychiatry Clin. Neurosci., 1997, 9, 482-497.

Maurice, T.; Martin-Fardon, R.; Romieu, P.; Matsumoto, R.R.

Sigma₁receptor antagonists represent a new strategy against co-

caine addiction and toxicity. Neurosci. Biobehav. Rev., 2002, 26,

499-527.

[24]

[25]

[26]

Dackis, C.A. Recent advances in the pharmacotherapy of cocaine

dependence. Curr. Psychiatry Rep., 2004, 6, 323-331.

Preti, A. New developments in the pharmacotherapy of cocaine

abuse. Addict Biol., 2007, 12, 133-151.

[4]

[5]

Matsumoto, R.R.; Liu, Y.; Lerner, M.; Howard, E.W.; Brackett,

D.J. Sigma receptors: potential medications development target for

anti-cocaine agents. Eur. J. Pharmacol., 2003, 469, 1-12.

Hanner, M.; Moebius, F.F.; Flandorfer, A.; Knaus, H.G.; Striess-

nig, J.; Kempner, E.; Glossmann, H. Purification, molecular clon-

ing, and expression of the mammalian sigma1-binding site. Proc.

Natl. Acad. Sci., 1996, 93, 8072-8077.

Karila, L.; Gorelick, D.; Weinstein, A.; Noble, F.; Benyamina, A.;

Coscas, S.; Blecha, L.; Lowenstein, W.; Martinot, J.L.; Reynaud,

M.; Lépine, J.P. New treatments for cocaine dependence: a focused

review. Int. J. Neuropsychopharmacol., 2008, 11, 425-438.

Cazenave Gassiot, A.; Charton, J.; Girault-Mizzi, S.; Gilleron, P.;

Debreu-Fontaine, M.-A.; Sergheraert, C. ; Melnyk, P. Synthesis

and pharmacological evaluation of Tic-Hydantoin derivatives as se-

lective ꢁ1 ligands. Part 2. Bioorg. Med. Chem. Lett., 2005, 15,

4828-4832.

Toussaint, M.; Delair, B.; Foulon, C.; Lempereur, N.; Vaccher, C.;

Maurice, T.; Melnyk, P. Tic hydantoin sigma-1 agonist: pharma-

cological characterization on cocaine-induced stimulant and appeti-

tive effects. Eur. Neuropsychopharmacol. 2009, 7, 504-515.

Toussaint, M.; Mousset, D.; Foulon, C.; Jacquemard, U.; Vaccher,

C.; Melnyk, P. Sigma-1 ligands: Tic-Hydantoin as a key pharma-

cophore. Eur. J. Med. Chem. 2010, 45 (1), 256-263.

[27]

[28]

[6]

Kekuda R.; Prasad P.D.; Fei Y.J.; Leibach, F.H.; Ganapathy, V.

Cloning and functional expression of the human type 1 sigma re-

ceptor (hSigmaR1). Biochem. Biophys. Res. Commun., 1996, 229,

553-558.

[7]

[8]

Seth, P.; Fei, Y.J.; Li, H.W.; Huang, W.; Leibach, F.H.; Ganapathy,

V. Cloning and functional characterization of a sigma receptor

from rat brain. J. Neurochem., 1998, 70, 922-931.

Prasad, P.D.; Li, H.W.; Fei, Y.J.; Ganapathy, M.E.; Fujita, T.;

Plumley, L.H.; Yang-Feng, T.L.; Leibach, F.H.; Ganapathy, V.

Exon-intron structure, analysis of promoter region, and chromoso-

mal localization of the human type 1 sigma receptor gene. J. Neu-

rochem., 1998, 70, 443-451.

[29]

[30]

Carson, K. G.; Harris, B. D.; Maryanoff, C. A.; Shad, R. D. Reduc-

tive Amination of Aldehydes and Ketones with Sodium Triace-

toxyborohydride. Studies on Direct and Indirect Reductive Amina-

tion Procedures. J. Org. Chem., 1996, 61, 3849-3862.

[9]

Hayashi, T.; Su, T.-P. Sigma-1 receptor chaperones at the ER-

mitochondrion interface regulate Ca²⁺signaling and cell survival.

Cell, 2007, 131, 596-610.

[10]

[11]

Matsumoto, R.R.; Bowen, W.D.; Sigma receptors. Chemistry, cell

biology and clinical implications. Springer press: New York, 2007.

Matsumoto, R.R.; McCracken, K.A.; Pouw, B.; Zhang, Y.; Bowen,

W.D. Involvement of sigma receptors in the behavioral effects of

cocaine: evidence from novel ligands and antisense oligodeoxynu-

cleotides. Neuropharmacology, 2002, 42, 1043-1055.

Matsumoto, R.R.; Hewett, K.L.; Pouw, B.; Bowen, W.D.; Hus-

bands, S.M.; Cao, J.J.; Hauck Newman, A. Rimcazole analogs at-

tenuate the convulsive effects of cocaine: correlation with binding

to sigma receptors rather than dopamine transporters. Neurophar-

macology, 2001, 41, 878-886.

Matsumoto, R.R.; McCracken, K.A.; Friedman, M.J.; Pouw, B.; De

Costa B.R.; Bowen, W.D. Conformationally restricted analogs of

BD1008 and an antisense oligodeoxynucleotide targeting sigma₁

receptors produce anti-cocaine effects in mice. Eur. J. Pharmacol.,

2001, 419, 163-174.

Matsumoto, R.R.; McCracken, K.A.; Pouw, B.; Zhang, Y.; Bowen,

W.D. Involvement of sigma receptors in the behavioral effects of

cocaine: evidence from novel ligands and antisense oligodeoxynu-

cleotides. Neuropharmacology, 2002, 42, 1043-1055.

[31]

[32]

[33]

Li, W.; Peng, S. Rational design and synthesis of unsaturated 2,5-

dioxopiperazine derivatives as potential protein tyrosine kinase in-

hibitors. Tetrahedron Lett., 1998, 39, 7373-7376.

Hätzelt, A.; Laschat, S.; Jones, P. G.; Grunenberg, J. Diastereose-

lective Alkylation of Tricyclic Lactim Ethers. Eur. J. Org. Chem.,

2002, 23, 3936-3943.

Eisenführ, A.; Arora, P. S.; Sengle, G.; Takaoka, L. R.; Nowick, J.

S.; Famulok, M. A ribozyme with michaelase activity: Synthesis of

the substrate precursors. Bioorg. Med. Chem., 2003, 11, 235-249.

Richard, F. B.; Aviv I. H. New method for the methylation of

amines. J. Org. Chem., 1972, 37, 1673-1674.

Glennon, R. A. Pharmacophore identification for sigma-1 (ꢁ1)

receptor binding: application of the "deconstruction-reconstruction-

elaboration" approach. Mini-reviews in Medicinal Chemistry, 2005,

5, 927-940.

[12]

[13]

[14]

[34]

[35]

[36]

Windhorst, A. D.; Timmerman, H.; Worthington, E. A.; Bijloo, G.

J.; Nederkoorn, P. H. J.; Menge, W. M. P. B.; Leurs, R.; Herscheid,

J. D. M. Characterization of the Binding Site of the Histamine H₃

Receptor. 2. Synthesis, in Vitro Pharmacology, and QSAR of a Se-

ries of Monosubstituted Benzyl Analogues of Thioperamide. J.

Med. Chem. 2000, 43, 1754-1761.

New Synthesis of Tic-Hydantoins Sigma-1 Ligands and Pharmacological Evaluation

Medicinal Chemistry, 2010, Vol. 6, No. 6 373

[37]

[38]

[39]

Ganapathy, M.E.; Prasad, P.D.; Huang, W.; Seth, P.; Leibach, F.H.;

Ganapathy, V. Molecular and ligand-binding characterization of

the sigma-receptor in the Jurkat human T lymphocyte cell line. J.

Pharmacol. Exp. Ther. 1999, 289, 251-260.

Bowen, W.D.; de Costa, B.R, Hellewell, S.B.; Thurkauf, A.;

Walker, M.; Rice, K.C. Characterization of [3H] (+)-pentazocine, a

highly selective sigma ligand. Prog. Clin. Biol. Res. 1990, 328,

117-120.

cedure of Xfit macro (Microsoft Excel). Inhibition constant value

Ki was calculated from the Cheng Prusoff equation (Ki =

IC₅₀/(1+[L]/K_D)), where [L] is the concentration of the radioligand

in the assay and K_D, the affinity of the radioligand for the receptor.

Cabordery, A.-C.; Toussaint, M.; Bonte, J.-P.; Melnyk, P.; Vac-

cher, C.; Foulon, C. Separation of Tic-hydantoin enantiomers, po-

tent sigma-1 agonist, by high performance liquid chromatography

and capillary electrophoresis. J. Chromatogr. A, 2010, 1217(24),

3871-3875.

[40]

IC₅₀values from competitive inhibition experiments were deter-

mined using the Marquardt-Levenberg non linear curve fitting pro-

Received: July 20, 2010

Revised: September 30, 2010

Accepted: October 05, 2010

Article Doi

New synthesis of tic-hydantoins sigma-1 ligands and pharmacological evaluation on cocaine-induced stimulant effects

DOI: 10.2174/157340610793563956

Source and publish data:

Authors:

Article abstract of DOI:10.2174/157340610793563956

Full text of DOI:10.2174/157340610793563956

Products guided by the article

R&D Labs maybe for 1263808-84-9

Relevant to this article

Hot Product