Stable azomethine imines having a 3,4-dihydroisoquinoline fragment and their cycloaddition to N-arylmaleimides

Article abstract of DOI:10.1134/S1070428011040129

Aroylation of 5,6,8,8a,13,14,16,16a-octahydro[1,2,4,5]tetrazino[6,1-a : 3,4-a']diisoquinoline or 1,3,4,8b-tetrahydro[1,2]diazireno[3,1-a]isoquinoline, as well as reactions of 2-(2-bromoethyl)benzaldehyde with aroylhydrazines followed by treatment with triethylamine, led to the formation of stable azomethine imines, aroyl(3,4-dihydroisoquinolinium-2-yl)azanides. 1,3-Dipolar cycloaddition of the latter to N-mesitylmaleimide was stereoselective: the ratio of the trans- and cis-adducts was (3-7) : 1, the former prevailing. The reactions with N-arylmaleimides having no ortho-substituents in the aryl group gave the corresponding cisadducts as the major products [trans/cis ratio 1 : (2.5-10)]. Pleiades Publishing, Ltd., 2011.

Full text of DOI:10.1134/S1070428011040129

ISSN 1070-4280, Russian Journal of Organic Chemistry, 2011, Vol. 47, No. 4, pp. 537–546. © Pleiades Publishing, Ltd., 2011.
Original Russian Text © Yu.B. Koptelov, S.P. Saik, A.P. Molchanov, 2011, published in Zhurnal Organicheskoi Khimii, 2011, Vol. 47, No. 4, pp. 538–545.
Stable Azomethine Imines Having a 3,4-Dihydroisoquinoline
Fragment and Their Cycloaddition to N-Arylmaleimides
Yu. B. Koptelov, S. P. Saik, and A. P. Molchanov
St. Petersburg State University, Universitetskii pr. 26, St. Petersburg, 198504 Russia
e-mail: koptelov@JK7283.spb.edu
Received July 7, 2010
Abstract—Aroylation of 5,6,8,8a,13,14,16,16a-octahydro[1,2,4,5]tetrazino[6,1-a:3,4-a′]diisoquinoline or
1,3,4,8b-tetrahydro[1,2]diazireno[3,1-a]isoquinoline, as well as reactions of 2-(2-bromoethyl)benzaldehyde
with aroylhydrazines followed by treatment with triethylamine, led to the formation of stable azomethine
imines, aroyl(3,4-dihydroisoquinolinium-2-yl)azanides. 1,3-Dipolar cycloaddition of the latter to N-mesityl-
maleimide was stereoselective: the ratio of the trans- and cis-adducts was ~(3–7):1, the former prevailing. The
reactions with N-arylmaleimides having no ortho-substituents in the aryl group gave the corresponding cis-
adducts as the major products [trans/cis ratio ~1:(2.5–10)].
DOI: 10.1134/S1070428011040129
Azomethine imines in which both nitrogen atoms or
one nitrogen and one carbon atoms are incorporated
into a polycyclic system are convenient synthons for
building up various heteropolycyclic, fused, and spiro-
cyclic systems often exhibiting biological activity [1].
A conventional method for generation of such azo-
methine imines is based on opening of the diaziridine
fragment at the carbon–nitrogen bond in fused bicyclic
systems. This process may be accompanied by re-
versible dimerization [2], isomerizations, and various
rearrangements [3, 4]. The presence of an electron-
withdrawing substituent in the α-position with respect
to the nitrogen atom in bicyclic diaziridine, e.g., of
an oxo group in 6-aryl-1,5-diazabicyclo[3.1.0]hexan-2-
ones, facilitates opening of the diaziridine ring due to
stabilization of the resulting azomethine imines, so that
it occurs even at room temperature [5]. Ortega et al. [6]
reported that aroylation of 1,3,4,8b-tetrahydro[1,2]di-
azireno[3,1-a]isoquinoline (I) afforded stable N-aroyl-
diaziridines II′ (Scheme 1). The authors assigned the
However, such chemical shift is quite untypical of
bicyclic diaziridines. For example, the 8b-H proton in
initial compound I resonates at δ 4.06 ppm [7], and in
1-methyl- and 1,3,3-trimethyl-1,3,4,8b-tetrahydro[1,2]-
diazireno[3,1-a]isoquinolines, at δ 3.36 ppm [8].
We presumed that the authors [6] isolated stable
azomethine imines II rather than diaziridines II′. We
reproduced the procedure reported in [6] and also syn-
thesized compounds IIa–IId in two ways: by ben-
zoylation of hexahydrotetrazinodiisoquinoline III and
by reaction of substituted benzoic acid hydrazides with
2-(2-bromoethyl)benzaldehyde (IV) in boiling ethanol,
followed by treatment of intermediate salts V with tri-
ethylamine (Scheme 2). In both cases, the products
were identical in physical properties to the compounds
prepared as described in [6]. Azomethine imine IId
was reported previously [9], and its preparation from
aldehyde IV has been described recently [10]. We
failed to detect signals of probable intermediates II′ in
the 1H NMR spectra of the reaction mixtures when the
aroylation of diaziridine I was carried out in chloro-
form-d at –20°C in the presence of triethylamine or
pyridine. Thus our results allow us to contend that
aroylation of I yields only the corresponding stable
azomethine imines IIa–IId.
1
signal at δ 9.67–9.77 ppm in the H NMR spectra of
the products to the CH proton in the diaziridine ring.
Scheme 1.
ArCOCl, pyridine
50–55°C
N
N
14–28%
1
The H NMR spectrum (CDCl3) of azomethine
NH
N
Ar
imine salt Va contained signals from methyl protons at
δ 2.37 ppm (3H, s), methylene protons at δ 3.46 (2H, t,
J = 8.0 Hz) and 4.53 ppm (2H, t, J = 8.0 Hz), aromatic
O
I
II'
537

KOPTELOV et al.
538
Scheme 2.
Br
Br
O
ArCONHNH2
O
Br–
N
N
CHO
IV
N
Ar
N
Ar
H
H
Va–Vd
Et3N
O
70–90%
N
N
Ar
IIa–IId
H
PhCOCl, Et3N
or pyridine
N
N
PhCOCl, pyridine
46%
IId
N
22%
N
N
NH
H
III
I
Ar = 4-MeC6H4 (a), 4-MeOC6H4 (b), 4-O2NC6H4 (c), Ph (d).
Scheme 3.
O
Ar'
O
Ar'
O
N
N
N
N
O
H
H
H
H
144°C
+
+
N
Ar
N
H
H
N
Ar'
O
O
O
O
N
N
O
Ar
VIa–VIk (trans)
Ar
VIIa–VIIk (cis)
IIa–IId
II, Ar′ = 4-MeC6H4 (a), 4-MeOC6H4 (b), 4-O2NC6H4 (c), Ph (d); VI, VII, Ar = 2,4,6-Me3C6H2, Ar′ = Ph (a), 4-MeC6H4 (b),
4-MeOC6H4 (c), 4-O2NC6H4 (d); Ar = Ph, Ar′ = Ph (e), 4-MeC6H4 (f), 4-MeOC6H4 (g), 4-O2NC6H4 (h); Ar = 4-BrC6H4, Ar′ = Ph (i),
4-MeC6H4 (j), 4-MeOC6H4 (k).
protons in the region δ 7.24–8.07 ppm (8H), 1-H at
δ 9.37 ppm (1H, s), and NH proton at δ 13.49 ppm
(1H). Azomethine imines IIa–IId characteristically
In continuation of our studies on the chemical be-
havior of azomethine imines having a 3,4-dihydroiso-
quinoline fragment [8, 11], we examined reactions of
compounds IIa–IId with N-arylmaleimides. The reac-
tions were carried out by heating the reactants in
boiling o-xylene (144°C) over a period of 2 h (TLC).
After removal of the solvent, the mixtures were ana-
1
displayed in the H NMR spectra (CDCl3) the follow-
ing signals, δ, ppm: 3.23–3.26 t (2H, J = 7.6 Hz) and
4.25–4.29 t (2H, J = 7.6 Hz) (3-H, 4-H), 6.84–8.15 m
(8H or 9H for IIa–IIc and IId, respectively), and 9.59–
9.75 m (HC=N); the position of the latter signal de-
pended on the water content in the sample or solvent.
1
lyzed by H NMR spectroscopy. The ratios of the
resulting trans- and cis-adducts VIa–VIk and VIIa–
VIIk were determined with an accuracy of ~5%
(Scheme 3, see table).
Ratios of trans (VIa–VIk) and cis adducts (VIIa–VIIk)
formed by 1,3-polar cycloaddition of azomethine imines
IIa–IId to N-arylmaleimides
The reactions of aroyl(3,4-dihydroisoquinolinium-
2-yl)azanides IIa–IId with N-mesitylmaleimide
resulted in the formation of mixtures of trans- and cis-
adducts VIa–VId and VIIa–VIId, the former prevail-
ing. According to our previous data, the cycloaddition
of di-ortho-substituted N-arylmaleimides to (3,4-dihy-
droisoquinolinium-2-yl)methylazanides [8] and aryl-
(3,4-dihydroisoquinolinium-2-yl)azanides [11] afford-
Ar′
Ar
Ph 4-MeOC6H4 4-MeC6H4 4-O2NC6H4
2,4,6-Me3C6H2 75:25
72:28
10:90
08:92
73:27
10:90
08:92
88:12
29:71
–
Ph
10:90
11:89
4-BrC6H4
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 47 No. 4 2011

STABLE AZOMETHINE IMINES HAVING A 3,4-DIHYDROISOQUINOLINE FRAGMENT
539
3.04
7.11H
2.57 H
2.73H
H
H2.70
H2.98
H3.49
H3.34
O
O
H7.86
N
N
7.39
4.84
H
4.8H2
7.94
N
N
7.41
6.14
5.81
H
7.44
H
H
H
4.14
4.01
O
O
O
1.82
Me
O
N
N
Me
Me
Me
2.15
2.07
7.03
7.03
2.28 Me
Me
VIa
VIIa
Principal nuclear Overhauser effects in the 2D NOESY 1H NMR spectra of stereoisomeric compounds VIa (DMSO-d6)
and VIIa (CDCl3).
ed exclusively the corresponding trans isomers. In
going from benzoyl derivative IId to 4-methylbenzoyl
and 4-methoxybenzoyl analogs IIa and IIb, the dia-
stereoselectivity [trans/cis ratio (72–75):(25–28)]
almost did not change, whereas the fraction of trans-
adduct VId in the reaction with azomethine imine IIc
having a strong electron-withdrawing nitro group in-
creased from 72–75 to 88%.
reaction with nitro-substituted compound IIc, the frac-
tion of trans isomer VId increased from ~10 to 29%.
The structure of adducts VI and VII was deter-
mined on the basis of the 2D NOESY 1H NMR spectra
of compounds VIa and VIIa. Figure shows the chem-
ical shifts of selected protons and principal nuclear
Overhauser effects (spatial interactions) in molecules
VIa and VIIa. Here, the most important coupling
is that between protons in the ortho-methyl group
(δ 2.15 ppm) and 11b-H resonating at δ 4.82 ppm. The
presence of the corresponding cross peak in the
NOESY spectrum of VIa allowed us to unambiguously
assign trans configuration of 11a-H and 11b-H in mol-
ecule VIa. The signal assignments made for adducts
VIa and VIIa were used to determine configuration of
the other cycloaddition products, compounds VIb–VIk
and VIIb–VIIk.
When N-arylmaleimides having no ortho-substit-
uents were used as dipolarophiles, the corresponding
cis-adducts predominated in the reactions mixtures
1
[according to the H NMR data, the cis/trans ratio for
azomethine imines IIa, IIb, and IId was ~(89–92):
(8–11)]. In the cycloadditions with (3,4-dihydroiso-
quinolinium-2-yl)methylazanides and aryl(3,4-dihy-
droisoquinolinium-2-yl)azanides, trans-adducts were
always formed as the major products [8, 11]. In the
Scheme 4.
26.1 kcal/mol
26.8 kcal/mol
O
N
N
Ph
E-IId
O
Ph
O
N
N
N
N
H
H
H
endo Approach
of N-phenylmaleimide
exo Approach
of N-phenylmaleimide
Ph
H
H
H
O
O
O
O
N
N
Ph
cis-VIIe
Ph
trans-VIIe
N
28.2 kcal/mol
30.9 kcal/mol
N
O
Ph
Z-IId
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 47 No. 4 2011

KOPTELOV et al.
540
Scheme 5.
Me
IIa–IId (Z)
IIa–IId (E)
Me
Ar
O
O
N
N
Me
Ar
O
O
O
N
O
endo Approach
exo Approach
H
N
N
O
H
N
X
N
O
N
N
X
O
X
O
O
N
O
Me
O
N
O
N
O
Ar
Ar
Me
Me
Quantum-chemical calculations in terms of the den-
sity functional theory [DFT, 6-31(d) basis set, B3LYP
functional; Gaussian-03 [12]) showed that the Z isomer
of azomethine imine IId is more energetically favor-
able (~98%). The endo approach of N-phenylmale-
imide to Z-IId is more probable than the exo approach
by a factor of ~25. In the cycloaddition to E-IId, the
endo approach of N-phenylmaleimide is more probable
than the exo approach by a factor of ~2 (Scheme 4).
These findings led us to presume that the cycloaddition
involves mainly the Z isomer of azomethine imine IId.
fragment, we can conclude that, unlike N-methyl- [8]
and N-aryl-substituted azomethine imines [11] for
which steric effect of the 3,4-dihydroisoquinoline frag-
ment was determining in 1,3-dipolar cycloaddition to
di-ortho-substituted N-arylmaleimides, the formation
of appreciable amounts of cis adducts in going to
N-aroyl-substituted azomethine imines indicates in-
creased contribution of their Z isomers and determin-
ing effect of the N-aroyl group on the cycloaddition
process.
EXPERIMENTAL
Analysis of possible dipolarophile approaches to
azomethine imines IIa–IId revealed that exo approach
of N-mesitylmaleimide to the Z isomers of II should be
hindered due to strong steric interaction between the
aroyl carbonyl group in II and mesityl group in male-
imide. endo Approach of N-mesitylmaleimide should
also be hindered due to steric interaction between the
C3H2C4H2 ethylene fragment in II and o-methyl group
in the imide. Presumably, preferential formation of
trans adducts in the reactions with sterically crowded
N-mesitylmaleimide is determined by participation of
less stable but more reactive E isomer of II and exo
approach of the dipolarophile. In the cycloadditions to
N-arylmaleimides having no substituents in the ortho
positions of the benzene ring, the endo approach to
predominating Z isomer of II is less sterically hindered
than the exo approach; therefore, the major products
are the corresponding cis adducts.
The IR spectra were recorded on a UR-20 spec-
trometer from 1–2% solutions in chloroform. The
NMR spectra were recorded on a Bruker DPX-300
spectrometer at 300.130 (1H) and 75.468 MHz (13C).
The chemical shifts were measured relative to the re-
sidual proton and carbon signals of deuterated solvents
(CHCl3, δ 7.26 ppm; CDCl3, δC 77.16 ppm; DMSO-d5,
δ 2.50 ppm; DMSO-d6; δC 39.52 ppm) [13]. The ele-
mental compositions were determined on a Hewlett–
Packard 185-B CHN analyzer. N-Arylmaleimides were
synthesized according to the procedure described in
[14]. 2-(2-Bromoethyl)benzaldehyde (IV) was pre-
pared by bromination of isochroman [15] which was
synthesized in turn by chloroformylation of β-phenyl-
ethyl alcohol [16].
1,3,4,8b-Tetrahydro[1,2]diazireno[3,1-a]isoquin-
oline (I) was synthesized from 9.3 g (71 mmol) of
3,4-dihydroisoquinoline as described in [7]. Yield 2.8 g
(28%), mp 97–98°C; published data [7]: mp 97–99°C.
Summarizing the data on cycloaddition reactions of
azomethine imines having a 3,4-dihydroisoquinoline
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 47 No. 4 2011

STABLE AZOMETHINE IMINES HAVING A 3,4-DIHYDROISOQUINOLINE FRAGMENT
541
1H NMR spectrum (CDCl3), δ, ppm: 2.30 d (1H, NH,
J = 6.9 Hz), 2.41 d.d.d (1H, CH2, J = 1.2, 4.2,
15.3 Hz), 2.72 d.d.d (1H, CH2, J = 4.2, 12.6, 13.1 Hz),
2.95 d.d.d (1H, CH2, J = 6.1, 12.6, 15.3 Hz), 3.58 d.d.d
(1H, CH2, J = 1.2, 6.1, 13.1 Hz), 4.06 d (1H, NCHN,
70°C, 10 mmol of 2-(2-bromoethyl)benzaldehyde (IV)
was added, and the mixture was heated to the boiling
point and was kept boiling for 1 h. Triethylamine,
30 mmol, was carefully added, and the mixture was
kept for 15 min more, cooled, and poured into cold
water. The precipitate was filtered off, dried under
reduced pressure at 60–70°C, and recrystallized from
THF with addition of hexane.
J = 6.9 Hz), 7.05–7.12 (1H, Harom), 7.21–7.33 (2H,
13
H
arom), 7.39–7.46 (1H, Harom). The C NMR spectrum
was consistent with that given in [6].
5,6,8,8a,13,14,16,16a-Octahydro[1,2,4,5]tetra-
zino[6,1-a:3,4-a′]diisoquinoline (III) was synthe-
sized from 4.2 g (0.02 mol) of 2-(2-bromoethyl)benz-
aldehyde (IV) as described in [16]. Yield 1.6 g (54%),
mp 242°C (decomp.); published data [16]: mp 247–
(3,4-Dihydroisoquinolinium-2-yl)(4-methylben-
zoyl)azanide (IIa). Yield 1.9 g (72%), mp 160–162°C;
published data [6]: mp 155–156°C.
(3,4-Dihydroisoquinolinium-2-yl)(4-methoxyben-
zoyl)azanide (IIb). Yield 2.2 g (79%), mp 156–157°C;
published data [6]: mp 164–165°C.
1
252°C. H NMR spectrum (DMSO-d6), δ, ppm: 3.22 t
(4H, CH2, J = 7.7 Hz), 3.67 t (4H, CH2, J = 7.7 Hz),
5.51 s (2H, CH), 7.10–7.34 (8H, Harom, NH), 7.45 d
(2H, Harom, J = 7.1 Hz).
(3,4-Dihydroisoquinolinium-2-yl)(4-nitroben-
zoyl)azanide (IIc). Yield 2.4 g (81%), mp 175–176°C;
published data [6]: mp 178–179°C.
Benzoyl(3,4-dihydroisoquinolinium-2-yl)azanide
(IId) [10]. a. A mixture of 1.00 g (6.8 mmol) of com-
pound I and 1.25 ml (9.0 mmol) of triethylamine in
5 ml of methylene chloride was cooled to –20°C, and
a solution of 1.06 g (7.5 mmol) of benzoyl chloride in
5 ml of methylene chloride was added dropwise at
such a rate that the temperature did not exceed –15°C.
The mixture was then shaken with water (3×5 ml), the
organic phase was separated and dried over sodium
sulfate, the solvent was distilled off, and the residue
was recrystallized from anhydrous tetrahydrofuran
with addition of hexane. Yield 374 mg (22%), bright
yellow powder which bleached on exposure to air due
Benzoyl(3,4-dihydroisoquinolinium-2-yl)azanide
(IId). Yield 1.9–2.2 g (76–88%).
2-(4-Methylbenzoylamino)-3,4-dihydroisoquino-
linium bromide (Vd). After addition of aldehyde IV,
a sample was withdrawn from the reaction mixture,
dissolved in chloroform-d, and analyzed by NMR.
1H NMR spectrum (CDCl3), δ, ppm: 2.37 s (3H, Me),
3.46 t (2H, CH2, J = 8.0 Hz), 4.53 t (2H, CH2, J =
8.0 Hz), 7.24 d (2Harom, J = 8.1 Hz), 7.43 d (1Harom, J =
7.6 Hz), 7.51 m (1H, Harom), 7.78 m (1H, Harom), 7.90 d
(1H, Harom, J = 7.6 Hz), 8.07 d (2H, Harom, J = 8.1 Hz),
13
9.37 s (1H, C=N+), 13.49 s (1H, NH). C NMR spec-
1
to formation of hydrate, mp 137–138°C. H NMR
trum (CDCl3), δC, ppm: 21.8 (CH3), 26.3 (CH2), 53.9
(CH2), 123.8 (Carom), 126.2 (Carom), 128.7 (CHarom),
128.8 (2C, CHarom), 129.0 (CHarom), 129.7 (2C,
CHarom), 134.9 (CHarom), 136.4 (Carom), 139.2 (CHarom),
144.8 (Carom), 165.0 (C=O), 166.2 (CH=N+).
spectrum (CDCl3), δ, ppm: 3.26 t (2H, CH2, J =
7.6 Hz), 4.29 t (2H, CH2, J = 7.6 Hz), 7.28–7.54 m
(7H, Harom), 8.10 m (2H, Harom), 9.63 s (1H, C=N+).
13C NMR spectrum (CDCl3), δC, ppm: 26.9 (CH2),
54.9 (CH2), 126.9 (Carom), 127.8 (CHarom), 128.1 (4C,
CHarom), 128.2 (CHarom), 129.9 (CHarom), 130.5
(CHarom), 133.5 (CHarom), 133.9 (Carom), 137.2 (Carom),
148.9 (CH=N+), 170.9 (C=O).
Reaction of azomethine imines IIa–IId with
N-arylmaleimides (general procedure). A suspension
of 1 mmol of azomethine imine IIa–IId (dried just
before use) and 1 mmol of the corresponding N-aryl-
maleimide in 2 ml of o-xylene was heated for 2 h at
140–145°C (oil bath) under stirring. The solvent was
distilled off under reduced pressure, and the residue
b. A suspension of 500 mg (1.7 mmol) of com-
pound III in 80 ml of pyridine was heated to 80°C, and
0.5 ml of benzoyl chloride was added dropwise over
a period of 30 min. The mixture was kept until it be-
came homogeneous and poured into water. The white
powder was filtered off and recrystallized from anhy-
drous tetrahydrofuran with addition of hexane. Yield
394 mg (46%).
1
was analyzed by H NMR. Solid residues (stereo-
isomer mixtures VIa/VIIa, VId/VIId, VIe/VIIe,
VIf/VIIf, VIg/VIIg, and VIk/VIIk) were recrystal-
lized from chloroform–methanol to isolate major prod-
ucts VId, VIIe, VIIf, VIIg, and VIIk. Mixtures
VIb/VIIb, VIc/VIIc, VIh/VIIh, VIi/VIIi, and
VIj/VIIj were not separated. The spectral parameters
of minor products and components of unseparated
Azomethine imines IIa–IId (general procedure).
A solution of 10 mmol of the corresponding substitut-
ed benzoic acid hydrazide in ethanol was heated to
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 47 No. 4 2011

KOPTELOV et al.
542
mixtures were determined from the spectra of the cor-
responding mixtures.
4.84 d (1H, CH, J = 9.2 Hz), 6.14 d (1H, CH, J =
9.0 Hz), 6.80 s (1H, Harom), 6.90 s (1H, Harom), 7.11 d
(1H, Harom, J = 7.3 Hz), 7.15–7.29 m (2H, Harom), 7.35–
7.51 m (4H, Harom), 7.81–7.88 m (2H, Harom). 13C NMR
spectrum (CDCl3), δC, ppm: 18.1 (CH3), 18.2 (CH3),
21.1 (CH3), 29.3 (CH2), 49.9 (CH2), 50.8 (CH), 59.7
(CH), 65.6 (CH), 127.0 (Carom), 127.1 (CHarom), 128.0
(2C, CHarom), 128.1 (CHarom), 128.3 (CHarom), 128.4
(CHarom), 129.6 (CHarom), 129.7 (3C, CHarom), 132.1
(CHarom), 132.3 (Carom), 132.5 (Carom), 133.5 (Carom),
135.2 (Carom), 135.7 (Carom), 139.8 (Carom), 168.9
(C=O), 170.4 (C=O), 173.6 (C=O). Found, %:
C 74.67; H 5.84; N 8.94. C29H27N3O3. Calculated, %:
C 74.82; H 5.85; N 9.03.
rel-(8aR,11aS,11bR)-8-Benzoyl-10-(2,4,6-tri-
methylphenyl)perhydropyrrolo[3′,4′:3,4]pyrazolo-
[5,1-a]isoquinoline-9,11-dione (VIa) and rel-
(8aR,11aS,11bS)-8-benzoyl-10-(2,4,6-trimethyl-
phenyl) perhydropyrrolo[3′,4′:3,4]pyrazolo[5,1-a]-
isoquinoline-9,11-dione (VIIa) were obtained from
azomethine imine IId and N-mesitylmaleimide. Yield
of mixture VIa/VIIa 417 mg (90%). The stereoisomer
mixture was separated by column chromatography on
silica gel (Silicagel L, 35–70 μm; substrate–sorbent
weight ratio 1:200; eluent hexane–ethyl acetate, 2:1);
the separation process was monitored by TLC (Silufol
UV-254; hexane–ethyl acetate, 1:1; development with
iodine vapor). According to the 1H NMR data, the ratio
of isomers VIa and VIIa in the reaction mixture was
~75:25.
rel-(8aR,11aS,11bR)-8-(4-Methylbenzoyl)-10-
(2,4,6-trimethylphenyl)perhydropyrrolo[3′,4′:3,4]-
pyrazolo[5,1-a]isoquinoline-9,11-dione (VIb) and
rel-(8aR,11aS,11bS)-8-(4-methylbenzoyl)-10-(2,4,6-
trimethylphenyl)perhydropyrrolo[3′,4′:3,4]pyra-
zolo[5,1-a]isoquinoline-9,11-dione (VIIb) were
obtained from azomethine imine IIa and N-mesityl-
maleimide. According to the 1H NMR data, the stereo-
isomer ratio VIb:VIIb in the reaction mixture was
~73:27.
Compound VIa. Yield 46 mg (10%), mp 250–
251°C (decomp.). IR spectrum, ν, cm–1: 3040, 3015,
2965, 2925, 2865, 1800, 1720 v.s, 1655, 1600, 1490,
1455, 1380 s, 1325, 1305, 1260, 1180 s, 1120, 1040,
1020. 1H NMR spectrum (CDCl3), δ, ppm: 2.11 s (3H,
Me), 2.22 s (3H, Me), 2.32 s (3H, Me), 2.58–2.73 m
(1H, CH2), 2.78–2.98 m (3H, CH2), 3.84 d.d (1H, CH,
J = 8.5, 8.6 Hz), 4.84 d (1H, CH, J = 8.5 Hz), 5.76 d
(1H, CH, J = 8.6 Hz), 6.94–7.01 m (2H, Harom), 7.05–
7.14 m (1H, Harom), 7.20–7.32 m (2H, Harom), 7.34–
7.44 m (2H, Harom), 7.45–7.54 m (1H, Harom), 7.55–
7.63 m (1H, Harom), 8.08 d (2H, Harom, J = 7.5 Hz).
13C NMR spectrum (CDCl3), δC, ppm: 17.9 (CH3),
18.1 (CH3), 21.2 (CH3), 29.0 (CH2), 49.0 (CH2), 51.4
(CH), 60.7 (CH), 66.2 (CH), 127.0 (Carom), 127.1
(CHarom), 128.0 (2C, CHarom), 128.1 (CHarom), 128.3
(CHarom), 128.4 (CHarom), 129.6 (CHarom), 129.7 (3C,
CHarom), 132.1 (CHarom), 132.3 (Carom), 132.5 (Carom),
133.5 (Carom), 135.2 (Carom), 135.7 (Carom), 139.8
(Carom), 168.9 (C=O), 170.4 (C=O), 173.6 (C=O).
Found, %: C 74.64; H 5.79; N 8.74. C29H27N3O3. Cal-
culated, %: C 74.82; H 5.85; N 9.03.
1
Compound VIb. H NMR spectrum (CDCl3), δ,
ppm: 2.11 s (3H, Me), 2.21 s (3H, Me), 2.31 s (3H,
Me), 2.40 s (3H, Me), 2.64–2.73 m (1H, CH2), 2.84–
2.98 m (3H, CH2), 3.83 d.d (1H, CH, J = 8.5, 8.6 Hz),
4.84 d (1H, CH, J = 8.6 Hz), 5.76 d (1H, CH, J =
8.5 Hz), 6.94–7.00 m (2H, Harom), 7.07–7.12 m (1H,
H
arom), 7.15–7.29 m (4H, Harom), 7.55–7.60 m (1H,
Harom), 8.00 d (2H, Harom, J = 8.1 Hz).
1
Compound VIIb. H NMR spectrum (CDCl3), δ,
ppm: 1.80 s (3H, Me), 2.01 s (3H, Me), 2.24 s (3H,
Me), 2.39 s (3H, Me), 2.71 m (1H, CH2, J = 16.1 Hz),
3.02 m (1H, CH2), 3.32 m (1H, CH2), 3.49 m (1H,
CH2), 4.09 d.d (1H, CH, J = 9.0, 9.2 Hz), 4.80 d (1H,
CH, J = 9.2 Hz), 6.14 d (1H, CH, J = 9.0 Hz), 6.80 s
(1H, Harom), 6.90 s (1H, Harom), 7.11 m (1H, Harom), 7.17–
7.29 m (5H, Harom), 7.78 d (2H, Harom, J = 8.1 Hz).
Compound VIIa. Yield 44 mg (9%), ratio VIIa:
VIa ≈ 91:9, mp 244–245°C (decomp.). IR spectrum,
ν, cm–1: 3040, 3015, 2965, 2925, 2860, 1800, 1720 v.s,
1655, 1600, 1490, 1455, 1380 s, 1325, 1305, 1280,
rel-(8aR,11aS,11bR)-8-(4-Methoxybenzoyl)-10-
(2,4,6-trimethylphenyl)perhydropyrrolo[3′,4′:3,4]-
pyrazolo[5,1-a]isoquinoline-9,11-dione (VIc) and
rel-(8aR,11aS,11bS)-8-(4-methoxybenzoyl)-10-
(2,4,6-trimethylphenyl)perhydropyrrolo[3′,4′:3,4]-
pyrazolo[5,1-a]isoquinoline-9,11-dione (VIIc) were
obtained from azomethine imine IIb and N-mesityl-
maleimide. According to the 1H NMR data, the stereo-
isomer ratio VIc:VIIc in the reaction mixture was
~72:28.
1
1260, 1215, 1190 s, 1130, 1040. H NMR spectrum
(CDCl3), δ, ppm: 1.82 s (3H, Me), 2.01 s (3H, Me),
2.24 s (3H, Me), 2.73 d.d.d (1H, CH2, J = 2.2, 3.3,
16.3 Hz), 3.04 m (1H, CH2, J = 5.2, 16.3 Hz), 3.34 m
(1H, CH2, J = 3.3, 10.5 Hz), 3.49 d.d.d (1H, CH2, J =
2.2, 5.2, 10.5 Hz), 4.14 d.d (1H, CH, J = 9.0, 9.2 Hz),
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STABLE AZOMETHINE IMINES HAVING A 3,4-DIHYDROISOQUINOLINE FRAGMENT
543
1
Compound VIc. H NMR spectrum (CDCl3), δ,
ppm: 2.11 s (3H, Me), 2.20 s (3H, Me), 2.31 s (3H,
Me), 2.63–2.73 m (1H, CH2), 2.84–2.99 m (3H, CH2),
3.82 d.d (1H, CH, J = 8.5, 8.6 Hz), 3.86 s (3H, OMe),
4.83 d (1H, CH, J = 8.7 Hz), 5.76 d (1H, CH, J =
8.6 Hz), 6.89 d (2H, Harom, J = 8.8 Hz), 6.95–6.99 m
(2H, Harom), 7.07–7.12 m (1H, Harom), 7.15–7.29 m
(2H, Harom), 7.57–7.61 m (1H, Harom), 8.14 d (2H,
Harom, J = 8.8 Hz).
1.97 s (3H, Me), 2.00 s (3H, Me), 2.20 s (3H, Me),
4.47 d.d (1H, CH, J = 8.9, 9.3 Hz), 4.93 d (1H, CH,
J = 9.3 Hz), 6.04 d (1H, CH, J = 8.9 Hz), 6.88 s
(1H, Harom), 6.95 s (1H, Harom), 7.95 d (2H, Harom
,
J = 8.6 Hz).
rel-(8aR,11aS,11bR)-8-Benzoyl-10-phenylperhy-
dropyrrolo[3′,4′:3,4]pyrazolo[5,1-a]isoquinoline-
9,11-dione (VIe) and rel-(8aR,11aS,11bS)-8-benzoyl-
10-phenylperhydropyrrolo[3′,4′:3,4]pyrazolo-
[5,1-a]isoquinoline-9,11-dione (VIIe) were obtained
from azomethine imine IId and N-phenylmaleimide.
1
Compound VIIc. Some signals in the H NMR
spectrum of mixture VIc/VIIc (CDCl3), δ, ppm: 1.79 s
(3H, Me), 2.01 s (3H, Me), 2.23 s (3H, Me), 2.74 m
(1H, CH2, J = 16.1 Hz), 3.02 m (1H, CH2), 3.33 m
(1H, CH2), 3.50 m (1H, CH2), 3.85 s (3H, OMe),
4.08 d.d (1H, CH, J = 9.1, 9.3 Hz), 4.82 d (1H, CH, J =
9.3 Hz), 6.14 d (1H, CH, J = 9.1 Hz), 6.80 s (1H,
1
According to the H NMR data, the ratio of stereo-
isomers VIe and VIIe in the reaction mixture was
~10:90.
Compound VIe. Some signals in the 1H NMR spec-
trum of mixture VIe/VIIe (DMSO-d6), δ, ppm:
3.89 d.d (1H, CH, J = 8.5, 9.1 Hz), 5.08 d (1H, CH, J =
9.1 Hz), 5.73 d (1H, CH, J = 8.5 Hz).
H
arom), 7.94 d (2H, Harom, J = 8.8 Hz).
rel-(8aR,11aS,11bR)-8-(4-Nitrobenzoyl)-10-
(2,4,6-trimethylphenyl)perhydropyrrolo[3′,4′:3,4]-
pyrazolo[5,1-a]isoquinoline-9,11-dione (VId) and
rel-(8aR,11aS,11bS)-8-(4-nitrobenzoyl)-10-(2,4,6-tri-
methylphenyl)perhydropyrrolo[3′,4′:3,4]pyrazolo-
[5,1-a]isoquinoline-9,11-dione (VIId) were obtained
from azomethine imine IIc and N-mesitylmaleimide.
Compound VIIe. Yield 300 mg (71%), mp 252–
253°C. IR spectrum, ν, cm–1: 3060, 3010, 2860, 1800,
1720 v.s, 1660, 1600, 1500, 1450, 1380 s, 1330, 1280,
1180 s, 1125, 1040, 1020. 1H NMR spectrum (CDCl3),
δ, ppm: 2.72 m (1H, CH2), 2.87–3.07 m (2H, CH2),
3.44 m (1H, CH2), 4.09 d.d (1H, CH, J = 8.6, 8.9 Hz),
4.76 d (1H, CH, J = 8.9 Hz), 6.07 d (1H, CH, J =
1
According to the H NMR data, the ratio of stereo-
8.6 Hz), 7.07–7.51 m (12H, Harom), 7.84 d (2H, Harom
,
isomers VId and VIId in the reaction mixture was
J = 7.1 Hz). 13C NMR spectrum (DMSO-d6), δC, ppm:
29.8 (CH2), 50.4 (CH2), 51.2 (CH), 61.1 (CH), 65.4
(CH), 126.6 (CHarom), 127.3 (2C, CHarom), 128.0
(CHarom), 128.8 (2C, CHarom), 129.0 (3C, CHarom),
129.6 (CHarom), 130.1 (3C, CHarom), 131.1 (Carom),
131.7 (CHarom), 133.0 (Carom), 133.8 (Carom), 135.5
(Carom), 172.6 (C=O), 174.8 (C=O), 175.1 (C=O).
Found, %: C 73.53; H 5.03; N 9.71. C26H21N3O3. Cal-
culated, %: C 73.74; H 5.00; N 9.92.
~88:12.
Compound VId. Yield 298 mg (61%), mp 266–
268°C. IR spectrum, ν, cm–1: 3040, 2925, 2860, 1800,
1720 v.s, 1655, 1600, 1525, 1490, 1415, 1380 s,
1345 s, 1320, 1305, 1280, 1180 s, 1120, 1040, 1020.
1H NMR spectrum (DMSO-d6), δ, ppm: 2.08 s (3H,
Me), 2.18 s (3H, Me), 2.29 s (3H, Me), 2.58–2.77 m
(3H, CH2), 3.03 m (1H, CH2), 4.06 d.d (1H, CH, J =
7.8, 8.9 Hz), 4.87 d (1H, CH, J = 8.9 Hz), 5.84 d (1H,
CH, J = 7.8 Hz), 7.03 s (2H, Harom), 7.15 m (1H,
rel-(8aR,11aS,11bR)-8-(4-Methylbenzoyl)-10-
phenylperhydropyrrolo[3′,4′:3,4]pyrazolo[5,1-a]iso-
quinoline-9,11-dione (VIf) and rel-(8aR,11aS,11bS)-
8-(4-methylbenzoyl)-10-phenylperhydropyrrolo-
[3′,4′:3,4]pyrazolo[5,1-a]isoquinoline-9,11-dione
(VIIf) were obtained from azomethine imine IIa and
Harom), 7.26 m (2H, Harom), 7.37 m (1H, Harom), 8.18 d
(2H, Harom, J = 8.1 Hz), 8.29 d (2H, Harom, J = 8.1 Hz).
13C NMR spectrum (DMSO-d6), δC, ppm: 17.4 (CH3),
17.7 (CH3), 20.6 (CH3), 28.2 (CH2), 48.8 (CH2), 51.6
(CH), 60.9 (CH), 64.5 (CH), 123.1 (2C, CHarom), 126.4
(CHarom), 127.2 (Carom), 127.7 (2C, CHarom), 128.3
(CHarom), 128.9 (CHarom), 129.1 (CHarom), 130.4 (2C,
CHarom), 132.4 (Carom), 132.5 (Carom), 135.4 (Carom),
135.7 (Carom), 138.8 (Carom), 140.0 (Carom), 149.0
(Carom), 165.7 (C=O), 170.7 (C=O), 173.3 (C=O).
Found, %: C 68.27; H 5.16; N 10.69. C29H26N4O5. Cal-
culated, %: C 68.22; H 5.13; N 10.97.
1
N-phenylmaleimide. According to the H NMR data,
the ratio of stereoisomers VIf and VIIf in the reaction
mixture was ~10:90.
Compound VIf. Some signals in the 1H NMR spec-
trum of mixture VIf/VIIf (DMSO-d6), δ, ppm: 3.89 d.d
(1H, CH, J = 8.5, 9.0 Hz), 5.08 d (1H, CH, J = 9.0 Hz),
5.72 d (1H, CH, J = 8.5 Hz).
1
Compound VIId. Some signals in the H NMR
spectrum of mixture VId/VIId (DMSO-d6), δ, ppm:
Compound VIIf. Yield 253 mg (58%), mp 272–
273°C. IR spectrum, ν, cm–1: 3060, 3010, 2970, 2925,
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KOPTELOV et al.
544
2860, 1800, 1720 v.s, 1650, 1610, 1500, 1460, 1410,
1380 s, 1330, 1305, 1290, 1260, 1180 s, 1120, 1060,
1010. H NMR spectrum (DMSO-d6), δ, ppm: 2.33 s
Found, %: C 71.46; H 5.10; N 9.15. C27H23N3O4. Cal-
culated, %: C 71.51; H 5.11; N 9.27.
1
rel-(8aR,11aS,11bR)-8-(4-Nitrobenzoyl)-10-
phenylperhydropyrrolo[3′,4′:3,4]pyrazolo[5,1-a]iso-
quinoline-9,11-dione (VIh) and rel-(8aR,11aS,11bS)-
8-(4-nitrobenzoyl)-10-phenylperhydropyrrolo-
[3′,4′:3,4]pyrazolo[5,1-a]isoquinoline-9,11-dione
(VIIh) were obtained from azomethine imine IIc and
(3H, Me), 2.63–2.89 m (3H, CH2), 3.47 m (1H, CH2),
4.31 d.d (1H, CH, J = 8.9, 9.3 Hz), 4.70 d (1H, CH, J =
9.0 Hz), 5.92 d (1H, CH, J = 8.6 Hz), 7.09–7.21 m
(5H, Harom), 7.24 d (2H, Harom, J = 7.8 Hz), 7.37–
7.43 m (2H, Harom), 7.46 d (2H, Harom, J = 7.8 Hz),
7.64 d (2H, Harom, J = 8.0 Hz). 13C NMR spectrum
(DMSO-d6), δC, ppm: 21.0 (CH3), 28.8 (CH2), 49.4
(CH2), 50.1 (CH), 60.1 (CH), 64.5 (CH), 125.6
(CHarom), 126.3 (2C, CHarom), 127.0 (CHarom), 128.0
(CHarom), 128.3 (2C, CHarom), 128.4 (2C, CHarom),
128.5 (CHarom), 129.1 (3C, CHarom), 130.1 (Carom),
131.4 (Carom), 132.0 (Carom), 132.8 (Carom), 140.7
(Carom), 171.4 (C=O), 173.9 (C=O), 174.2 (C=O).
Found, %: C 74.02; H 5.33; N 9.50. C27H23N3O3. Cal-
culated, %: C 74.12; H 5.30; N 9.60.
1
N-phenylmaleimide. According to the H NMR data,
the ratio of stereoisomers VIh and VIIh in the reaction
mixture was ~29:71.
Compound VIh. Some signals in the 1H NMR spec-
trum of mixture VIh/VIIh (DMSO-d6), δ, ppm: 3.90 m
(1H, CH, J = 8.3 Hz), 4.80 m (1H, CH), 5.71 d (1H,
CH, J = 8.3 Hz).
1
Compound VIIh. H NMR spectrum (DMSO-d6),
δ, ppm: 2.60–2.84 m (3H, CH2), 3.26 m (1H, CH2),
4.24 d.d (1H, CH, J = 8.5, 8.7 Hz), 4.78 d (1H, CH, J =
8.7 Hz), 5.88 d (1H, CH, J = 8.5 Hz), 6.97–7.20 m
(5H, Harom), 7.26–7.39 m (3H, Harom), 7.40–7.48 m
(1H, Harom), 7.86 d (2H, Harom, J = 8.6 Hz), 8.16 d (2H,
Harom, J = 8.7 Hz).
rel-(8aR,11aS,11bR)-8-(4-Methoxybenzoyl)-10-
phenylperhydropyrrolo[3′,4′:3,4]pyrazolo[5,1-a]iso-
quinoline-9,11-dione (VIg) and rel-(8aR,11aS,11bS)-
8-(4-methoxybenzoyl)-10-phenylperhydropyrrolo-
[3′,4′:3,4]pyrazolo[5,1-a]isoquinoline-9,11-dione
(VIIg) were obtained from azomethine imine IIb and
rel-(8aR,11aS,11bR)-8-Benzoyl-10-(4-bromo-
phenyl)perhydropyrrolo[3′,4′:3,4]pyrazolo-
[5,1-a]isoquinoline-9,11-dione (VIi) and rel-
(8aR,11aS,11bS)-8-benzoyl-10-(4-bromophenyl)per-
hydropyrrolo[3′,4′:3,4]pyrazolo[5,1-a]isoquinoline-
9,11-dione (VIIi) were obtained from azomethine
imine IId and N-(4-bromophenyl)maleimide. Accord-
ing to the 1H NMR data, the ratio of stereoisomers VIi
and VIIi in the reaction mixture was ~11:89.
1
N-phenylmaleimide. According to the H NMR data,
the ratio of stereoisomers VIg and VIIg in the reaction
mixture was ~10:90.
Compound VIg. Some signals in the 1H NMR spec-
trum of mixture VIg/VIIg (CDCl3), δ, ppm: 4.13 d.d
(1H, CH, J = 8.5, 8.7 Hz), 4.79 d (1H, CH, J = 8.5 Hz),
5.72 d (1H, CH, J = 8.7 Hz), 8.17 (2H, Harom, J =
8.9 Hz).
Compound VIi. Some signals in the 1H NMR spec-
trum of mixture VIi/VIIi (DMSO-d6), δ, ppm: 3.82 m
(1H, CH, J = 8.8 Hz), 4.79 m (1H, CH), 5.70 d (1H,
CH, J = 8.8 Hz), 8.09 d (2H, Harom, J = 7.2 Hz).
Compound VIIg. Yield 285 mg (63%), mp 212–
213°C. IR spectrum, ν, cm–1: 3080, 3040, 3010, 2970,
2940, 2900, 2860, 2845, 1800, 1720 v.s, 1640, 1605 s,
1500, 1460, 1425, 1380 s, 1340, 1310, 1260, 1180 s,
1
1
Compound VIIi. H NMR spectrum (CDCl3), δ,
1130, 1060, 1040, 1010. H NMR spectrum (CDCl3),
ppm: 2.71 m (1H, CH2), 2.83–3.07 m (2H, CH2), 3.44 m
(1H, CH2), 4.08 d.d (1H, CH, J = 8.6, 8.8 Hz), 4.76 d
(1H, CH, J = 8.8 Hz), 6.06 d (1H, CH, J = 8.6 Hz),
7.02–7.13 m (3H, Harom), 7.18–7.31 m (2H, Harom),
7.32–7.43 m (3H, Harom), 7.46 m (1H, Harom), 7.53 d
(2H, Harom, J = 8.6 Hz), 7.82 d (2H, Harom, J = 7.6 Hz).
δ, ppm: 2.75 m (1H, CH2), 2.94 m (1H, CH2), 3.08 m
(1H, CH2), 3.50 m (1H, CH2), 3.83 s (3H, OMe),
4.06 d.d (1H, CH, J = 8.7, 8.9 Hz), 4.75 d (1H, CH, J =
8.9 Hz), 6.09 d (1H, CH, J = 8.7 Hz), 6.89 d (2H,
Harom, J = 8.8 Hz), 7.08–7.42 m (9H, Harom), 7.93 d
13
(2H, Harom, J = 8.8 Hz). C NMR spectrum (CDCl3),
δC, ppm: 29.6 (CH2), 50.1 (CH2), 50.2 (CH), 55.4
(OCH3), 59.7 (CH), 65.8 (CH), 113.2 (2C, CHarom),
125.6 (Carom), 125.7 (2C, CHarom), 126.3 (CHarom),
127.9 (CHarom), 128.6 (CHarom), 128.7 (CHarom), 129.0
(CHarom), 129.2 (2C, CHarom), 129.4 (Carom), 131.5
(2C, CHarom), 131.6 (Carom), 133.0 (Carom), 162.1
(Carom), 170.6 (C=O), 173.2 (C=O), 173.7 (C=O).
rel-(8aR,11aS,11bR)-10-(4-Bromophenyl)-8-(4-
methylbenzoyl)perhydropyrrolo[3′,4′ : 3,4]pyrazolo-
[5,1-a]isoquinoline-9,11-dione (VIj) and rel-
(8aR,11aS,11bS)-10-(4-bromophenyl)-8-(4-methyl-
benzoyl)perhydropyrrolo[3′,4′:3,4]pyrazolo[5,1-a]-
isoquinoline-9,11-dione (VIIj) were obtained from
azomethine imine IIa and N-(4-bromophenyl)male-
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1
imide. According to the H NMR data, the ratio of
stereoisomers VIj and VIIj in the reaction mixture
was ~8:92.
(3H, Harom), 7.52 d (2H, Harom, J = 8.5 Hz), 7.92 d (2H,
arom, J = 8.7 Hz). 13C NMR spectrum (CDCl3), δC,
H
ppm: 29.5 (CH2), 50.2 (CH2), 50.3 (CH), 55.5 (OCH3),
59.7 (CH), 65.9 (CH), 113.2 (2C, CHarom), 122.6
(Carom), 125.4 (Carom), 126.3 (CHarom), 127.3 (2C,
CHarom), 128.0 (CHarom), 128.6 (CHarom), 128.9
(CHarom), 129.3 (Carom), 130.6 (Carom), 131.5 (2C,
CHarom), 132.4 (2C, CHarom), 133.0 (Carom), 162.2
(Carom), 170.5 (C=O), 172.9 (C=O), 173.4 (C=O).
Found, %: C 60.88; H 4.22; N 7.63. C27H22BrN3O4.
Calculated, %: C 60.91; H 4.17; N 7.89.
Compound VIj. Some signals in the 1H NMR spec-
trum of mixture VIj/VIIj (DMSO-d6), δ, ppm: 3.81 m
(1H, CH2, J = 8.4 Hz), 4.78 m (1H, CH2), 5.69 d (1H,
CH2, J = 8.4 Hz), 8.01 d (2H, Harom, J = 7.8 Hz).
Compound VIIj. Yield 316 mg (61%), mp 255–
256°C. IR spectrum, ν, cm–1: 3040, 3010, 2970, 2930,
2860, 1800, 1720 v.s, 1650, 1605, 1495, 1380 s, 1325,
1
1305, 1285, 1260, 1180 s, 1130, 1080, 1020. H NMR
spectrum (CDCl3), δ, ppm: 2.38 (3H, Me), 2.72 m (1H,
CH2), 2.85 m (1H, CH2), 3.03 m (1H, CH2), 3.46 m
(1H, CH2), 4.07 d.d (1H, CH, J = 8.7, 9.0 Hz), 4.74 d
(1H, CH, J = 9.0 Hz), 6.09 d (1H, CH, J = 8.7 Hz),
7.01–7.14 m (3H, Harom), 7.16–7.39 m (5H, Harom),
7.52 d (2H, Harom, J = 8.5 Hz), 7.76 d (2H, Harom, J =
8.1 Hz). 13C NMR spectrum (DMSO-d6), δC, ppm:
21.0 (CH3), 28.8 (CH2), 49.5 (CH2), 50.2 (CH), 60.1
(CH), 64.5 (CH), 121.5 (Carom), 125.6 (CHarom), 127.0
(CHarom), 128.1 (CHarom), 128.3 (2C, CHarom), 128.4
(4C, CHarom), 129.0 (CHarom), 130.1 (Carom), 131.2
(Carom), 131.3 (Carom), 132.1 (2C, CHarom), 132.8
(Carom), 140.7 (Carom), 171.4 (C=O), 173.6 (C=O),
174.0 (C=O). Found, %: C 62.71; H 4.24; N 8.01.
C27H22BrN3O3. Calculated, %: C 62.80; H 4.29; N 8.14.
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rel-(8aR,11aS,11bR)-10-(4-Bromophenyl)-8-(4-
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1
1305, 1260, 1180 s, 1130, 1080, 1040, 1020. H NMR
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