4-Thio derivatives of dibenzosuberone: Potential antidepressant compounds

Article abstract of DOI:10.2174/157017810791514634

This work describes the synthesis of a series of nine 4-thio dibenzosuberone derivatives (10,11-dihydro-5Hdibenzo[ a,d]cycloheptane-5-one derivatives). Ullmann's reaction was used to synthesize six 4-thio dibenzosuberone derivatives 10-15 from 4-iodo dibe

Full text of DOI:10.2174/157017810791514634

Letters in Organic Chemistry, 2010, 7, 383-387
383
4-Thio Derivatives of Dibenzosuberone: Potential Antidepressant
Compounds
Paulo R.C. Martins*, Gilberto A. Romeiro and Carlos M.R. Ribeiro
Programa de Pós-Graduação em Química Orgânica, Departamento de Química Orgânica, Instituto de Química,
Universidade Federal Fluminense (UFF), Outeiro de S. J. Batista, Valonguinho, s/n, Centro, Niterói, Rio de Janeiro,
CEP 24020-150, Brazil
Received June 25, 2009: Revised December 07, 2009: Accepted March 30, 2010
Abstract: This work describes the synthesis of a series of nine 4-thio dibenzosuberone derivatives (10,11-dihydro-5H-
dibenzo[a,d]cycloheptane-5-one derivatives). Ullmann´s reaction was used to synthesize six 4-thio dibenzosuberone
derivatives 10-15 from 4-iodo dibenzosuberone 9. Compound 9 was synthesized from dibenzosuberone 7 through the use
of TTFA [thallium (III) trifluoroacetate] and KI. Hydrolysis of 10 yielded derivative 14. Compound 17, which was
prepared through the chlorination of 14, was aminated to furnish 4-thio derivative 18.
Keywords: Dibenzocycloheptane, dibenzosuberone, thio compounds, Ullmann reaction, thallium (III) salts, tricyclic
antidepressants.
INTRODUCTION
acetate] was used despite the lower reactivity for that carbon
[14].
Molecules bearing a tricyclic core have been synthesized
by many research groups due to their various effects on the
central nervous system (CNS) [1]. Thioxanthenes 1 [2],
phenothiazines 2 [3], dibenzoxapines 3 [4], dibenzothiepines
4 [5], dibenzazepines 5 [6] and the dibenzocycloheptanes 6
[7] are some examples of this class of molecules with
activity on the CNS. Dibenzosuberone 7, which shares the
basic structure of 6, has been used to produce derivatives
containing halide, amino, oxa, thio and other groups as
substituents at aromatic carbons 1-3 and 6-9 as well as at
saturated carbons 10 and 11 [8]. In contrast, not many
examples have been described in the literature of analogs of
8 with substituents at carbon-4 (Fig. (1) [9, 10].
S
S
N
R
(1) thioxanthene
(2) phenothiazine
X
N
R
3 dibenzoxapine (X= O)
4 dibenzothiepine (X=S)
5 dibenzazepines
Due to our interest in this class of compounds we have
previously described the synthesis of some 4-amino
10
11
1
9
derivatives of dibenzosuberone
7 (10,11-dihydro-5-H-
2
8
dibenzo[a,d]cycloheptane-5-one) [10] as well as some
benzocycloheptanequinoline derivatives [6a]. Preliminary
evaluations have shown antidepressant-like effects for some
of these 4-amino derivatives [11]. These results prompted us
to develop a synthetic sequence to prepare derivatives 8 with
thio group bonded to C-4 of dibenzosuberone 7.
5
3
7
4
6
X
Y
6 dibenzocycloheptane (X= H,H; Y=H)
7 dibenzosuberone (X=O; Y=H)
8 4-thiodibenzosuberone derivatives (X=O; Y= -SR)
The Ullmann reaction involves a copper promoted
coupling between alkyl halides and amines [12]. More
recently, many research groups have modified this reaction
to N-, O- and S-arylation by aryl halides [13]. We decided to
employ these modified Ullmann reactions to thiolate iodo-
dibenzocycloheptane 6. To install the iodine at carbon-4 of
6, a thallium III reagent [TTFA (thallium (III) trifluoro-
R= alkyl group
Fig. (1). Tricyclics systems with CNS activities.
RESULTS AND DISCUSSION
To synthesize the derivatives of 4, dibenzosuberone 7
was treated with TTFA (tallium (III) trifluoroacetate) in TFA
(trifluoroacetic acid) for 48 h at 25°C. This was followed by
a reaction with KI leading to 4-iodo-dibenzosuberone 9 in
83% yield[15]. An Ullmman type reaction was employed to
prepare 4-thio dibenzosuberone derivatives 10-15 from 4-
iodo-dibenzosuberone 9 in moderate yields (Scheme 1). In
*Address correspondence to this author at the Programa de Pós-Graduação
em Química Orgânica, Departamento de Química Orgânica, Instituto de
Química, Universidade Federal Fluminense (UFF), Outeiro de S. J. Batista,
Valonguinho, s/n, Centro, Niterói, Rio de Janeiro, CEP 24020-150, Brazil;
Tel: 55-21-2629.2149; Fax: 55-21-2629-2135;
E-mail: paulocodeco@vm.uff.br
1570-1786/10 $55.00+.00
© 2010 Bentham Science Publishers Ltd.

384 Letters in Organic Chemistry, 2010, Vol. 7, No. 5
Martins et al.
1) TTFA; TFA;
48h; 25oC
HS-R; DMF
Cuo; 75oC
2) KI
O
O
I
O
S
(7) dibenzosuberone
(9) 4-iodo-dibenzosuberone (83%)
R
(10) R = -CH2CH2NCHO (50%)
(11) R = -CH2CH2N(CH3)2 (45%)
(12) R = -CH2CH2N(CH2CH3)2 (47%)
(13) R = -CH2CH2Ph (43%)
(14) R = -CH2CH2OH (53%)
(15) R = -CH2CH2CO2H (75%)
Scheme 1. 4-thio derivatives (10-15) from dibenzosuberone (7).
these reactions, 4-iodo derivative 9 was treated with Cuo and
4-iodo-10,11-dihydro-5H-dibenzo[a,d]cycloheptane-5-one
(9) (4-iodo-dibenzosuberone)
the corresponding thiol reagent in DMF at 75°C.
Derivative 10 was used as starting material to prepare 16.
For this purpose, 16 was obtained via hydrolysis of 10 in
62% yield in refluxing sulfuric acid. Derivative 17 was
prepared from 14 in 74% yield via a substitution reaction in
refluxing SOCl2. Halide 17 was treated with a piperazine
derivative to yield 4-thio dibenzosuberone 18 in 61% yield
(Scheme 2).
TTFA (thallium (III) trifluoroacetate, 25g, 65.5 mmol)
was added to a solution of dibenzosuberone 7 (10 g, 51.5
mmol) in 25 mL of trifluoroacetic acid. The reaction was
stirred in the dark at room temperature for 48 hours. A
solution of KI (28g, 168.7 mmol) in 20 mL of water was
then added slowly to the reaction. The reaction was stirred at
room temperature for 30 minutes during which time, a
precipitate formed. While stirring, sodium metabisulfide was
slowly added until the reaction color changed. The reaction
was then treated with a 4N KOH solution. The reaction was
subsequently filtered and the solid was washed with a hot
CHCl3. The aqueous solution was extracted with CHCl3. The
combined organic layers were washed with brine, dried over
anhydrous Na2SO4 and evaporated under reduced pressure.
The resulting residue was recrystallized from ethanol. Yield:
EXPERIMENTAL
General
All solvents and reagents used were supplied by E.
Merck or Aldrich Co. TLC: silica gel 60 F254 plates (0.25
mm; Merck). Column chromatography (CC): silica gel 60
(0.040-0.063 mm; Merck). Melting points were determined
1
on a Fischer-Johns apparatus: uncorrected. H-NMR (300
1
83%. Oil; H NMR (300 MHz, CDCl3) ꢀ (ppm) [15]: 3.08-
MHz) and 13C-NMR (75.5 MHz) spectra: Varian 7T
instrument in CDCl3 (Me4Si as internal standard); chemical
shifts are in ppm and coupling constants are given in Hz. IR
spectra were recorded on films or KBr pellets with a Perkin
Elmer 1420 spectrometer. Low-resolution EI mass spectra
were recorded on a Finnigan MAT-711 instrument, at 70 eV
with the source at 200oC and with an accelerating voltage of
8KV.
3.13 (2H, m), 3.22-3.25 (2H, m), 7.02 (1H, t, 7.8 Hz), 7.18
(1H, d, 7.5Hz), 7.19 (1H, d, 8.4 Hz), 7.33 (1H, t, 7.5 Hz),
7.44 (1H, t, 7.8 Hz), 7.45 (1H, d, 7.8 Hz), 7.86 (1H, d, 7.8
Hz). 13C NMR (75 MHz, CDCl3) ꢀ (ppm): 32.8; 34.5; 91.9;
126.4; 127.3; 129,7; 130.2; 131.3; 132.2; 137.8; 138.2;
139.1; 140.3; 141.8; 199.9.
H2SO4;
reflux; 5h
O
O
S
S
NHCHO
NH2
(10)
(16) 62%
SOCl2;
reflux; 6h
NH(CH2CH2)2NCH2OH
150oC; 6h
O
O
S
O
S
S
OH
Cl
(14)
(17) 74%
N
HO
N
(18) 61%
Scheme 2. derivatives (16), (17) and (18) synthesis.

4-Thio Derivatives of Dibenzosuberone
Letters in Organic Chemistry, 2010, Vol. 7, No. 5
385
General Procedure for the Preparation of 4-thio
Dibenzosuberone Derivatives 10-15
130.2; 130.4; 132.1; 135.1; 138.1; 139.5; 140.9; 141.5;
198.4. EI-MS [m/z (%)]: 339 (1, [M]+.), 239 (17), 208 (10),
178 (10), 86(100), 71 (18), 57(65), 44(18). IR (KBr) (ꢀ cm-
1): 3401m, 3056m, 2968s, 2810m, 2429w, 1943w, 1788w,
1659s, 1596s, 1580s, 1449s, 1357s, 1296s, 1256s, 1198w,
1156w, 1102w, 1068w, 991w, 854w, 924s, 833m, 782m,
754m, 724m, 696w, 646w, 665w, 611w.
A round-bottom flask equipped with a magnetic stirrer and
condenser was charged with 4-iodo-dibenzosuberone 9 (0.3
g, 0.89 mmol), the appropriate thiol (1 eq.), Cu0 (0.04g, 1.37
o
mmol) and 3 mL of DMF. The reaction was stirred at 75 C
for 5-24 hours, depending on the thiol used. The solution
was then filtered and the solid was washed with 50 mL of
CHCl3. The aqueous solution was extracted with CHCl3. The
combined organic layers were washed with brine, dried over
anhydrous MgSO4 and the solvent was evaporated under
reduced pressure. The residue was then purified by silica gel
column chromatography.
4-[(2-phenylethyl)sulfanyl]-10,11-dihydro-5H-dibenzo[a,d]
cyclohepten-5-one (13)
1
Yield: 43%. m.p.: 82-83oC; H NMR (300 MHz, CDCl3)
ꢀ (ppm): 2.81-2.87 (2H, m); 3.07-3.14 (4H, m), 3.23-3.27
(2H, m); 7.02 (1H, dd, 5.4 and 3.0 Hz); 7.08-7.24 (5H, m);
7.10 (1H, dd, 8.1 and 1.8 Hz), 7.27 (1H, d, 5.4 Hz), 7.28
(1H, d, 3.0 Hz), 7.32 (1H, dt, 7.5 and 1.2 Hz), 7.42 (1H, dt,
7.5 and 1.5 Hz), 7.95 (1H, dd, 7.8 and 1.5 Hz). 13C NMR (75
MHz, CDCl3) ꢀ (ppm): 32.7; 34.8; 34.9; 35.8; 124.6; 126.2;
126.3 (2C); 128.3 (3C); 130.1; 130.3; 132.1; 135.7; 138.1;
139.5; 140.0; 141.2; 198.3. EI-MS [m/z (%)]: 344 (10,
[M]+.), 239 (100), 178 (17), 152(5), 77(5). IR (KBr) (ꢀ cm-1):
3059m, 3026m, 2920s, 2855m, 1944w, 1660s, 1597s, 1589s,
1495m, 1451s, 1423s, 1357m, 1296s, 1253s, 1179w, 1156w,
1137w, 1100w, 1073w, 1053w, 1029w, 954w, 924s, 833m,
805w, 781m, 723m, 697m, 665w, 646m, 611m.
2-[(5-oxo-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-4-
yl)sulfanyl]ethylformamide (10)
Yield: 50%. oil; 1H NMR (300 MHz, CDCl3) ꢀ (ppm): 3.04-
3.10 (2H, m), 3.04-3.11 (2H, m), 3.22-3.26 (2H; m); 3.42-
3.48 (2H; m); 6.73 (1H, sl); 7.12 (1H, dd, 7.5 and 1.2 Hz),
7.19 (1H, dd, 7.8 and 0.9 Hz), 7.29 (1H, d, 7.8 Hz), 7.34
(1H, d, 1.2 Hz), 7.38 (1H, dt, 7.8 and 1.5 Hz), 7.44 (1H, dt,
7.5 and 1.5 Hz), 7.90 (1H, dd, 7.8 and 1.5 Hz), 8.10 (1H, s).
13C NMR (75 MHz, CDCl3) ꢀ (ppm): 32.6; 34.6; 34.9; 36.3;
125.9; 126.3; 129.2; 129.4; 130.3; 130.5; 132.2; 132.4;
138.1; 139.5; 140.8; 161.1; 199.9. EI-MS [m/z (%)]: 311 (5,
[M]+.), 293 (10), 266(30), 239 (100), 178 (15), 83 (25). IR
4-[(2-hydroxyethyl)sulfanyl]-10,11-dihydro-5H-dibenzo[a,d]
cyclohepten-5-one (14)
1
Yield: 53%. oil; H NMR (300 MHz, CDCl3) ꢀ (ppm):
(film) (ꢀ cm-1): 3308s, 3055s, 2922s, 2859s, 2753w, 1947w,
1663s, 1596s, 1580s, 1520m, 1449m, 1424m, 1385m, 1357m,
1296s, 1257s, 1191w, 1157w, 1157w, 1137w, 1101w,
1077w, 1053w, 1033w, 955w, 924s, 873w, 832m, 783s,
754m, 724s, 697w, 646w, 665w, 611w.
3.07-3.11 (2H, m); 3.19-3.25 (2H, m); 3.69 (2H, t, 5.7 Hz),
7.11 (1H, dd, 7.5 and 1.2 Hz); 7.18 (1H, dd, 7.8 and 1.2 Hz),
7.28 (1H, d, 7.8 Hz), 7.34 (1H, dd, 7.8 and 1.2 Hz), 7.40
(1H, dd, 7.8 and 1.5 Hz), 7.44 (1H, dt, 7.2 and 1.5 Hz), 7.92
(1H, dd, 7.5 and 1.5 Hz). 13C NMR (75 MHz, CDCl3) ꢀ
(ppm): 32.3; 34.4; 37.6; 59.8; 125.5; 126.1; 129.4; 128.9;
130.0; 130.2; 132.00; 132.9; 137.9; 139.1; 140.6; 142.6;
199.5. EI-MS [m/z (%)]: 284 (8, [M]+.), 266(10), 239 (100),
178 (15), 83(17). IR (film) (ꢀ cm-1): 3428s, 2924s, 1651s,
1449m, 1257m, 665s.
4-{[2-(dimethylamino)ethyl]sulfanyl}-10,11-dihydro-5H-
dibenzo[a,d]cyclohepten-5-one (11)
Yield: 45%. m.p.: 103-104oC; 1H NMR (300 MHz,
CDCl3) ꢀ (ppm): 2.97-3.02 (2H, m), 3.05-3.09 (2H, m), 3.15-
3.21 (2H; m); 2.24 (3H; s); 2.49-2.54 (2H, m); 7.03 (1H, dd,
5.7 and 2.7 Hz); 7.17 (1H, dd, 7.8 and 0.9 Hz), 7.29 (1H, d,
5.7 Hz), 7.30 (1H, d, 2.4 Hz), 7.33 (1H, dd, 7.5 and 1.5 Hz),
7.42 (1H, dt, 7.5 and 1.5 Hz), 7.95 (1H, dd, 7.8 and 1.5 Hz).
13C NMR (75 MHz, CDCl3) ꢀ (ppm): 31.3; 32.7; 34.7; 45.0;
58.0; 124.7; 126.2; 126.5; 130.0; 130.1; 130.3 (2C); 135.5;
138.1; 139.4; 140.8; 198.3. EI-MS [m/z (%)]: 312 (10,
[M+1]+.), 239 (60), 208 (20), 191 (10), 178 (30), 71 (50), 58
(100). IR (KBr) (ꢀ cm-1): 3059s, 2940m, 2856m, 2818m,
2778m, 1657s, 1596m, 1578m, 1450m, 1424m, 1357s, 1296s,
1256s, 1156w, 1136w, 1098w, 1041w, 1007w, 957w, 924s,
832w, 783m, 757w, 724m, 696w, 647w, 665w, 610w.
3-[(5-oxo-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-4-yl)
sulfanyl]propanoic acid (15)
Yield: 75%. m.p.: 191-192 oC; 1H NMR (300 MHz,
DMSO) ꢀ (ppm): 2.56 (2H, t, 7.5 Hz); 3.11-3.15 (2H, m),
3.18 (2H, t, 7.5 Hz); 3.28-3.32 (2H; m); 7.28 (1H, dd, 6.9
and 0.9 Hz); 7.40 (1H, d, 7.5 Hz), 7.45-7.54 (3H, m), 7.63
(1H, dt, 7.8 and 1.5 Hz), 7.85 (1H, dd, 7.8 and 1.2 Hz), 12.45
(1H, sl). 13C NMR (75 MHz, DMSO) ꢀ (ppm): 27.8; 32.0;
33.4; 34.4; 125.0; 125.8; 126.4; 129.4; 130.0; 131.0; 132.8;
135.0; 137.7; 139.6; 140.5; 141.2; 172.7; 197.7. EI-MS [m/z
(%)]: 312 (10, [M]+.), 239 (100), 208 (75), 180(47), 165 (27),
149(20), 105(19), 89(25), 73(20). IR (KBr) (ꢀ cm-1): 2953w,
1718s, 1648s, 1597m, 1578m, 1427m, 1405m, 1301m,
1261m, 1240m, 1213w, 955w, 924w, 833w, 791m, 755m,
723m, 696w, 647w, 608w.
4-{[2-(diethylamino)ethyl]sulfanyl}-10,11-dihydro-5H-di-
benzo[a,d]cyclohepten-5-one (12)
1
Yield: 47%. m.p.: 65oC; H NMR (300 MHz, CDCl3) ꢀ
4-[(2-aminoethyl)sulfanyl]-10,11-dihydro-5H-dibenzo[a,d]
cyclohepten-5-one (16)
(ppm): 0.98 (3H, t, 7.2 Hz); 2.95-3.02 (2H, m), 3.06-3.09
(2H, m), 3.22-3.25 (2H; m); 2.65-2.66 (2H; m); 2.52 (2H, q,
7.2Hz); 7.02 (1H, dd, 6.9 and 1.5 Hz); 7.18 (1H, d, 7.5 Hz),
7.29 (1H, d, 6.9 Hz), 7.30 (1H, d, 1.5 Hz), 7.33 (1H, dd, 7.8
and 1.5 Hz), 7.42 (1H, dt, 7.5 and 1.5 Hz), 7.96 (1H, dd, 7.8
and 1.5 Hz). 13C NMR (75 MHz, CDCl3) ꢀ (ppm): 11.1;
30.5; 32.7; 34.8; 46.8; 51.4; 124.9; 126.3; 126.8; 130.0;
A round-bottom flask equipped with a magnetic stirrer
and condenser was charged with 4-thio dibenzosuberone 10
(0.5 g, 1.7 mmol) and 10 mL of H2SO4. The reaction was
stirred at reflux for 5 hours. After this time, the reaction
solution was neutralized with a solution of 10% NaOH. The

386 Letters in Organic Chemistry, 2010, Vol. 7, No. 5
Martins et al.
aqueous solution was extracted with CHCl3. The combined
organic layers were washed with brine, dried over anhydrous
MgSO4 and the solvent was evaporated under reduced
pressure. After that, the residue was purified by silica gel
column chromatography eluting first with CHCl3, followed
by AcOEt and MeOH. Yield: 62%. Oil; 1H NMR (300 MHz,
CHCl3) ꢀ (ppm): 2.84 (2H, t, 6.0 Hz); 2.98 (2H, t, 6.0 Hz);
3.04-3.08 (2H, m), 3.20-3.24 (2H, m); 7.03 (1H, dd, 6.3 and
2.1 Hz); 7.17 (1H, dd, 7.8 and 0.9 Hz), 7.26 (1H, d, 6.6 Hz),
7.28 (1H, d, 2.1 Hz), 7.32 (1H, dd, 7.8 and 1.2 Hz), 7.41
(1H, dt, 7.5 and 1.5 Hz), 7.93 (1H, dd, 7.8 and 1.5 Hz). 13C
NMR (75 MHz, CHCl3) ꢀ (ppm): 32.6; 34.6; 37.6; 40.2;
125.0; 126.4; 127.3; 129.7; 130.1; 130.3; 132.0; 134.3;
138.0; 139.9; 140.7; 141.9; 198.7. EI-MS [m/z (%)]: 283(6,
[M]+.), 264(100), 239 (80), 222(23), 208(57), 178 (40),
165(25), 152(13), 89(21), 77 (18), 57(16). IR (film) (ꢀ cm-1):
3053m, 2922m, 2859m, 1659s, 1616w, 1596m, 1581w,
1484w, 1450m, 1424m, 1357w, 1297w, 1257w, 1191w,
1157w, 1137w, 1102w, 1025w, 954w, 924m, 832w, 781m,
735s, 707m, 646m, 611w.
34.7; 52.4 (2C); 52.5 (2C); 59.1; 124.7; 126.2; 126.5; 130.0;
130.2; 130.3; 132.1; 135.4; 138.0; 139.5; 140.8; 141.3. EI-
MS [m/z (%)]: 396(1, [M]+.), 380(10), 239 (70), 178 (15),
157(65), 143(100), 100(25), 70(28), 56(17). IR (film) (ꢀ cm-
1): 3375s, 3054s, 2941s, 2817s, 1658s, 1597s, 1580m, 1449s,
1357m, 1298s, 1257s, 1155m, 1055w, 1006w, 955w, 924m,
876w, 833w, 782m, 734s, 700m, 665w, 647w, 611w.
ACKNOWLEDGEMENTS
We gratefully acknowledge CAPES, CNPq and FAPERJ.
CONCLUSION
This work describes the synthesis of nine 4-thio
dibenzosuberone derivatives 10-18 (4-thio-10,11-dihydro-
5H-dibenzo [a,d] cycloheptane-5-one derivatives) which are
potential antidepressant agents. To prepare intermediates 9,
thallium III reagents were employed to iodinate the
appropriate position of the tricyclic system. A modified
Ullmman reaction then furnished the 4-thio derivatives in
good to moderate yields, representing an efficient
methodology for the synthesis of this class of compounds.
4-[(2-chloroethyl)sulfanyl]-10,11-dihydro-5H-dibenzo[a,d]
cyclohepten-5-one (17):
A round-bottom flask equipped with a magnetic stirrer
and condenser was charged with 4-thio dibenzosuberone 14
(0.4 g, 1.4 mmol) and 5 mL of SOCl2. The reaction was
stirred at reflux for 6 hours. After this time, the reaction
solution was concentrated under reduced pressure. The
residue was purified by silica gel column chromatography
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1
eluting with CHCl3. Yield: 74%. Oil; H NMR (300 MHz,
CHCl3) ꢀ (ppm): 3.07-3.11 (2H, m); 3.19-3.26 (4H, m), 3.50-
3.58 (2H, m); 7.10 (1H, dd, 5.4 and 3.0 Hz); 7.18 (1H, dd,
7.5 and 0.6 Hz), 7.32 (1H, d, 5.4 Hz), 7.33 (1H, d, 3.0 Hz),
7.33 (1H, dd, 7.8 and 0.9 Hz), 7.43 (1H, dt, 7.5 and 1.5 Hz).
13C NMR (75 MHz, CHCl3) ꢀ (ppm): 32.7; 34.7; 35.9; 41.9;
125.8; 126.4; 127.8; 129.9; 130.2; 130.5; 132.2; 133.2;
138.0; 139.7; 140.7; 142.6; 198.3. EI-MS [m/z (%)]: 304(4,
[M+2]+.), 302(12, [M]+), 266(25), 239 (100), 208(20),
178(30), 165(12), 152(10), 63(10). IR (film) (ꢀ cm-1):
3056m, 2920m, 2857m, 1942w, 1856w, 1659s, 1596s, 1581s,
1484m, 1446s, 1423s, 1357m, 1296s, 1256s, 1214m, 1190w,
1156m, 1137m, 1101w, 1053w, 1036w, 955w, 924s, 871w,
832m, 805w, 782s, 754m, 722m, 697m, 665w, 610m.
[2]
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A round-bottom flask equipped with a magnetic stirrer
and condenser was charged with 4-thio dibenzosuberone 17
(0.2 g, 0.66 mmol) and 1-(2-hydroxyethyl)piperazine (1 mL,
8 mmol). The reaction was stirred at 150°C for 6 hours.
After this time, 50 mL of CHCl3 was added and the organic
layer was washed with water (4 x 30 mL). The solvent of
organic layer was dried over anhydrous MgSO4, and
evaporated under reduced pressure after which the residue
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eluent CHCl3, followed by AcOEt and MeOH. Yield: 61%.
[3]
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1
Oil; H NMR (300 MHz, CHCl3) ꢀ (ppm): 2.37-2.73 (10H,
m); 2.98-3.03 (2H, m), 3.05-3.09 (2H, m); 3.22-3.25 (2H,
m); 7.03 (1H, dd, 5.4 and 3.0 Hz); 7.18 (1H, d, 7.5 Hz), 7.27
(1H, d, 5.4 Hz), 7.28 (1H, d, 3.0 Hz), 7.33 (1H, dd, 7.8 and
0.9 Hz), 7.42 (1H, dt, 7.5 and 1.5 Hz), 7.93 (1H, dd, 7.8 and
1.5Hz). 13C NMR (75 MHz, CHCl3) ꢀ (ppm): 30.7; 32.7;

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