Synthesis of new partially hydrogenated carbazoles

Article abstract of DOI:10.1134/S107042800703013X

Bromination of 2,5-dimethyl-, 2-methoxy-, and 2-methyl-6-(cyclohex-2-en-1- yl)-N-(p-tolylsulfonyl)anilines in the presence of a base gave the corresponding N-(p-tolylsulfonyl) derivatives of 1-bromo-, 1,5-dibromo-, and 1,6-dibromo-1,2,3,4,4a,9a-hexahydroc

Full text of DOI:10.1134/S107042800703013X

ISSN 1070-4280, Russian Journal of Organic Chemistry, 2007, Vol. 43, No. 3, pp. 409–413. © Pleiades Publishing, Ltd., 2007.
Original Russian Text © R.R. Gataullin, N.A. Likhacheva, I.B. Abdrakhmanov, 2007, published in Zhurnal Organicheskoi Khimii, 2007, Vol. 43, No. 3,
pp. 410–414.
Synthesis of New Partially Hydrogenated Carbazoles
R. R. Gataullin, N. A. Likhacheva, and I. B. Abdrakhmanov
Institute of Organic Chemistry, Ufa Research Center, Russian Academy of Sciences,
pr. Oktyabrya 71, Ufa, 450054 Bashkortostan, Russia
e-mail: chemorg@anrb.ru
Received May 10, 2006; revised November 26, 2006
Abstract—Bromination of 2,5-dimethyl-, 2-methoxy-, and 2-methyl-6-(cyclohex-2-en-1-yl)-N-(p-tolylsul-
fonyl)anilines in the presence of a base gave the corresponding N-(p-tolylsulfonyl) derivatives of 1-bromo-,
1,5-dibromo-, and 1,6-dibromo-1,2,3,4,4a,9a-hexahydrocarbazoles which underwent dehydrobromination to
3,4,4a,9a-tetrahydrocarbazole derivatives on heating in piperidine.
DOI: 10.1134/S107042800703013X
as well as their 6- or 5-bromo derivatives from the cor-
responding 2-(cyclohex-2-en-1-yl)anilines [4].
Alkaloids of the pyridocarbazole series [1, 2]
exhibit antitumor activity; therefore, development of
new methods for the synthesis of such heterocycles
remains important up to now [3]. In most syntheses of
this sort, carbazoles or their partially hydrogenated
precursors are key intermediates. In the present work
we made an attempt to synthesize partially hydrogenat-
ed 5,8-dimethyl-, 8-methyl-, and 8-methoxycarbazoles,
1-Bromohexahydrocarbazoles IV–VI were obtain-
ed in almost quantitative yield by cyclization of
N-(p-tolylsulfonyl)anilines I–III by the action of bro-
mine in the presence of sodium hydrogen carbonate.
The subsequent bromination of IV gave compound
VII as a result of electrophilic replacement of hydro-
Scheme 1.
Br
H
Br2, NaHCO3
CH2Cl2
H
Br
N
Ts
OMe
R2
VIII
R2
R2
H
H
Br2, NaHCO3
CH2Cl2
Br2, NaHCO3
CH2Cl2
Br
H
Br
H
Br
N
N
NHTs
Ts
IV–VI
Ts
R1
R1
R1
I–III
VII, IX
CHO
Me
Me
H
R2
H
Ph
N
POCl3
C6H4Cl2-o
Piperidine
110°C
R3
H
H
N
N
Ts
Ts
Me
R1
XVI
X–XV
I, IV, VII, X, XIII; R1 = R2 = Me; III, VI, IX, XII, XV, R1 = Me, R2 = H; II, V, XI, R1 = MeO, R2 = H; XIV, R1 = MeO, R2 = Br;
X–XII, XIV, R3 = H; XIII, XV, R3 = Br.
409

GATAULLIN et al.
410
gen on C6 by bromine. An analogous reaction of V
with Br2 afforded 5-bromo derivative VIII as the
major product. The position of the halogen atom was
bon signals in the 13C NMR spectrum of VII differs
from that observed in the spectrum of initial mono-
bromo derivative IV [6].
1
determined on the basis of the H NMR data. In the
1H NMR spectrum of dibromide VIII, the 6-H and
7-H protons resonated as two doublets at δ 6.68 and
7.22 ppm with a coupling constant J of 8.9 Hz. Two
two-proton doublets were assigned to the p-tolylsul-
fonyl group (δ 7.30 and 7.98 ppm). Presumably, the
minor product is the corresponding 7-bromo isomer.
EXPERIMENTAL
1
13
The H and C NMR spectra were recorded from
solution in CDCl3 on a Bruker AM-300 instrument
operating at 300.13 and 75.45 MHz, respectively; the
chemical shifts were measured relative to tetramethyl-
silane as internal reference. The elemental composi-
tions were determined on an M-185B CHN Analyzer.
Column chromatography was performed on silica gel
(40–70 μm; Lancaster). Silica gel plates (Lyuminofor,
Russia) were used for qualitative TLC analysis; spots
were visualized under UV light (λ 254 nm) or by treat-
ment with iodine vapor. The melting points were deter-
mined on a Boetius melting point apparatus.
When a mixture of hexahydrocarbazole VI with Br2
in methylene chloride was stirred on exposure to light,
it turned colorless, presumably as a result of bromina-
tion of the solvent. After appropriate treatment, the
initial compound was recovered from the reaction
mixture. We succeeded in obtaining compound IX by
bromination of VI in the dark. The position of bromine
1
at C6 was determined on the basis of the H NMR
spectrum which contained two one-proton singlets at
δ 6.92 and 7.30 ppm belonging to 5-H and 7-H. On
heating in piperidine, compounds IV–IX underwent
dehydrohalogenation to tetrahydrocarbazoles X–XV.
N-[2-(Cyclohex-2-en-1-yl)-3,6-dimethylphenyl]-
p-toluenesulfonamide (I). p-Toluenesulfonyl chloride,
3.09 g (15 mmol), was added at room temperature to
a solution of 2 g (10 mmol) of 2-(cyclohex-2-en-1-yl)-
2,5-dimethylaniline [4] in 15 ml of pyridine. After
24 h, the mixture was diluted with 20 ml of H2O,
stirred for 30 min, and evaporated under reduced pres-
sure. The residue was dissolved in 40 ml of chloro-
form, the solution was washed with water (2×20 ml),
10% aqueous NaHCO3 (20 ml), and water again
(20 ml) and dried over Na2SO4, the solvent was
removed under reduced pressure, and crude product I,
3.45 g (98%), was recrystallized from ethanol. Yield
Our attempt to effect formylation of N-(p-tolylsul-
fonyl)aniline I at the para position with respect to the
amino group by heating with N-methyl-N-phenylform-
amide in dichlorobenzene in the presence of POCl3
resulted in the formation of hexahydrocarbazole XVI
as the only product; compound XVI is used as inter-
mediate product in some syntheses [5] of Ellipticine.
The cyclohexene ring in molecule I contains no func-
tional groups which could favor introduction of other
substituents.
1
3.36 g (96%), mp 190–193°C (from EtOH). H NMR
spectrum, δ, ppm: 1.39–2.22 m (6H, CH2); 1.98 s,
2.32 s, and 2.45 s (3H each, CH3); 3.98 m (1H, 1'-H);
5.58 m (2H, 2'-H, 3'-H); 6.92 d (1H, 4-H); 6.98 d (1H,
5-H); 7.27 d (2H, 3''-H, 5''-H, J = 8.2 Hz); 7.69 d (2H,
2''-H, 6''-H, J = 8.2 Hz). Found, %: C 70.67; H 6.82;
N 3.73; S 8.76. C21H25NO2S. Calculated, %: C 70.95;
H 7.09; N 3.94; S 9.02.
The upfield regions of the 1H NMR spectra of com-
pounds IV and VII are almost similar. The doublet of
doublets from 9a-H in the spectra of IV–IX is charac-
terized by two large coupling constants, indicating
nearly axial orientation of that proton (J9a,1 ≈ 9–10 Hz)
and cis-junction of the cyclohexane and pyrrole rings
(J9a,4a = 6.4–6.7 Hz). The axial orientation of 1-H also
follows from the corresponding large coupling con-
stants J9a,1 ≈ 9–10 Hz and J1,2-ax ≈ 12 Hz, while the
small coupling constant J1,2-eq = 4.5–5.0 Hz suggests
interaction between 1-H and 2-Heq. The 4a-H is likely
to occupy equatorial position, for it is not characterized
by large coupling constants, and its signal appears in
Compounds II and III were synthesized in a similar
way.
N-[2-(Cyclohex-2-en-1-yl)-6-methoxyphenyl]-
p-toluenesulfonamide (II) was obtained from 5 g
(25 mmol) of 2-(cyclohex-2-en-1-yl)-6-methoxy-
aniline. Yield 8.56 g (96%), mp 178–180°C (from
1
1
the H NMR spectrum as a poorly resolved multiplet.
EtOH). H NMR spectrum, δ, ppm: 1.25–2.15 m (6H,
The 6-H and 7-H protons in the aromatic ring of IV
resonate as two one-proton singlets. In the H NMR
spectrum of VII only a singlet at δ 7.37 ppm (7-H) is
present. In addition, the multiplicity of aromatic car-
CH2), 2.40 s (3H, CH3), 3.15 s (3H, OCH3), 4.35 m
(1H, 1'-H), 5.60–5.88 m (2H, 2'-H, 3'-H), 6.15 s (1H,
NH), 6.47 d.d (1H, 5-H, J1 = 1.2, J2 = 8.2 Hz), 6.94 d.d
(1H, 3-H, J1 = 1.2, J2 = 8.0 Hz), 7.18 m (3H, Harom),
1
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 43 No. 3 2007

SYNTHESIS OF NEW PARTIALLY HYDROGENATED CARBAZOLES
411
1
13
0.98 g (80%), mp 176–177°C (from EtOH). H NMR
spectrum, δ, ppm: 1.10–2.30 m (6H, CH2), 2.43 s (3H,
CH3), 3.60–3.75 m (2H, 1-H, 4a-H), 3.76 s (3H,
OCH3), 4.90 d.d (1H, 9a-H, J1 = 6.7, J2 = 9.7 Hz),
6.70 d (1H, 7-H, J = 7.5 Hz), 6.80 d (1H, 5-H, J =
7.2 Hz), 7.15 d.d (1H, 6-H, J1 = 7.2, J2 = 7.5 Hz),
7.30 d (2H, 3'-H, 5'-H, J = 8.3 Hz), 8.0 d (3H, 2'-H,
7.51 d (2H, 2''-H, 6''-H, J = 8.3 Hz). C NMR spec-
trum, δC, ppm: 21.3 (CH3); 21.5, 24.8, 31.3 (C4', C5',
C6'); 36.3 (C1'); 54.5 (OCH3); 107.7 (C5); 121.0, 128.1,
128.9, 130.7 (C3, C4, C2', C3'); 127.5, 128.6 (C2'', C6'',
C3'', C5''); 122.2, 136.6, 143.0, 147.2 (C1, C2, C1'', C4'');
153.9 (C6). Found, %: C 67.18; H 6.57; N 4.00; S 8.82.
C20H23NO3S. Calculated, %: C 67.20; H 6.49; N 3.92;
S 8.97.
13
6'-H, J = 8.3 Hz). C NMR spectrum, δC, ppm: 21.5
(CH3); 22.2, 23.9 (C3, C4); 36.3 (C2); 44.3 (C4a); 52.5
(C1); 55.7 (OCH3); 73.3 (C9a); 112.1, 115.0, 127.4 (C5,
C6, C7); 128.2 (C3', C5'); 128.6 (C2', C6'); 130.6, 137.9,
139.2, 143.3 (C4b, C1', C8a, C4'); 152.6 (C8). Found,
%: C 55.15; H 5.02; Br 18.41; N 3.28; S 7.23.
C20H22BrNO3S. Calculated, %: C 55.05; H 5.08;
Br 18.31; N 3.21; S 7.35.
N-[2-(Cyclohex-2-en-1-yl)-6-methylphenyl]-
p-toluenesulfonamide (III) was obtained from 5 g
(26.9 mmol) of 2-(cyclohex-2-en-1-yl)-6-methyl-
aniline. Yield 8.23 g (90%), mp 169–170°C (from
1
EtOH). H NMR spectrum, δ, ppm: 1.25–2.50 m (6H,
CH2), 2.10 s and 2.40 s (3H each, CH3), 3.47 m (1H,
1'-H), 5.24 m (1H, 2'-H), 5.75 m (1H, 3'-H), 6.05 s
(1H, NH), 7.05–7.26 m (5H, Harom), 7.60 d (2H, 2''-H,
6''-H, J = 8.3 Hz). Found, %: C 70.18; H 6.57; N 4.05;
S 9.52. C20H23NO2S. Calculated, %: C 70.35; H 6.79;
N 4.10; S 9.39.
N-(1-Bromo-8-methyl-1,2,3,4,4a,9a-hexahydro-
9H-carbazol-9-yl)-p-toluenesulfonamide (VI) was
obtained from 1.0 g (2.9 mmol) of compound III.
Yield 1.17 g (96%), mp 215–220°C (from EtOH).
1H NMR spectrum, δ, ppm: 1.00–2.30 m (6H, CH2),
2.40 s (3H, CH3), 2.60 s (3H, CH3), 2.75 m (1H, 4a-H),
3.72 d.d.d (1H, 1-H, J1 = 4.0, J2 = 10.2, J3 = 13.5 Hz),
4.53 d.d (1H, 9a-H, J1 = 6.5, J2 = 10.2 Hz), 6.80 d (1H,
7-H, J = 7.0 Hz), 7.06–7.15 m (2H, 5-H, 6-H), 7.18 d
(2H, 3'-H, 5'-H, J = 8.1 Hz), 7.55 d (2H, 3'-H, 6'-H, J =
8.1 Hz). Found, %: C 57.03; H 5.22; Br 19.41; N 3.28;
S 7.83. C20H22BrNO2S. Calculated, %: C 57.15;
H 5.27; Br 19.01; N 3.33; S 7.63.
N-(1-Bromo-5,8-dimethyl-1,2,3,4,4a,9a-hexa-
hydro-9H-carbazol-9-yl)-p-toluenesulfonamide
(IV). A solution of 0.48 g (3 mmol) of bromine in 1 ml
of methylene chloride was added dropwise under stir-
ring to a solution of 1 g (3 mmol) of compound I in
10 ml of methylene chloride. The mixture was stirred
for 18 h at 20°C (the progress of the reaction was
monitored by TLC), diluted with 50 ml of methylene
chloride, and washed with a 10% solution of NaHCO3
(2×20 ml) and water (2×50 ml). The organic phase
was dried over Na2SO4, and the solvent was removed
under reduced pressure. Yield 0.99 g (82.5%),
N-(1,6-Dibromo-5,8-dimethyl-1,2,3,4,4a,9a-hexa-
hydro-9H-carbazol-9-yl)-p-toluenesulfonamide
(VII). A solution of 0.08 g (0.5 mmol) of bromine in
1 ml of methylene chloride was added dropwise under
stirring to a solution of 0.2 g (0.5 mmol) of compound
IV in 10 ml of methylene chloride. The mixture was
stirred for 18 h at 20°C (TLC), diluted with 50 ml of
methylene chloride, and washed with a 10% solution
of NaHCO3 (2×20 ml) and water (2×50 ml). The
organic phase was dried over Na2SO4, the solvent was
removed under reduced pressure, and the residue was
recrystallized from ethanol. Yield 0.22 g (95%),
1
mp 203–206°C (from EtOH). H NMR spectrum, δ,
ppm: 1.00–2.50 m (6H, CH2), 2.10 s (3H, CH3), 2.40 s
(3H, CH3), 2.55 s (3H, CH3), 3.12 m (1H, 4a-H),
3.70 d.d.d (1H, 1-H, J1 = 4.8, J2 = 9.7, J3 = 12.8 Hz),
4.35 d.d (1H, 9a-H, J1 = 6.4, J2 = 9.7 Hz), 6.85 d (1H,
Harom, J = 7.8 Hz), 7.02 d (1H, Harom, J = 7.8 Hz),
7.18 d (2H, Harom, J = 8.2 Hz), 7.57 d (2H, Harom, J =
13
8.2 Hz). C NMR spectrum, δC, ppm: 19.0, 19.2, 21.4
(CH3); 22.0, 24.5, 35.7 (CH2); 43.8 (C4a); 51.5 (C1);
71.9 (C9a); 127.6, 129.2, 129.6, 129.9 (C6, C7, C2', C6',
C3', C5'); 130.8, 131.4, 135.2, 135.6, 141.1, 143.9 (C4b,
C5, C8, C8a, C1', C4'). Found, %: C 57.84; H 5.24;
Br 17.91; N 2.87; S 7.01. C21H24BrNO2S. Calculated,
%: C 58.07; H 5.57; Br 18.40; N 3.22; S 7.40.
1
mp 143–145°C (from EtOH). H NMR spectrum, δ,
ppm: 0.95–2.40 m (6H, CH2), 2.23 s (3H, CH3), 2.43 s
(3H, CH3), 2.49 s (3H, CH3), 3.20 m (1H, 4a-H),
3.69 d.d.d (1H, 1-H, J1 = 5.0, J2 = 9.7, J3 = 12.5 Hz),
4.33 d.d (1H, 9a-H, J1 = 6.5, J2 = 9.7 Hz), 7.23 d (2H,
H
arom, J = 8.1 Hz), 7.37 s (1H, 7-H), 7.59 d (2H, Harom,
13
Compounds V and VI were synthesized in a similar
J = 8.1 Hz). C NMR spectrum, δC, ppm: 18.8, 19.1,
21.6 (CH3); 22.0, 24.9 (C3, C4); 35.6 (C2); 44.7 (C4a);
51.2 (C1); 71.8 (C9a); 127.9, 129.4, 133.9 (C7, C2', C6',
C3', C5'); 123.8, 131.3, 132.6, 135.4, 137.6, 140.8,
144.3 (C4b, C5, C6, C8, C8b, C1', C4'). Found, %: C 48.79;
way.
N-(1-Bromo-8-methoxy-1,2,3,4,4a,9a-hexahydro-
9H-carbazol-9-yl)-p-toluenesulfonamide (V) was
obtained from 1 g (2.8 mmol) of compound II. Yield
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 43 No. 3 2007

GATAULLIN et al.
412
13
H 4.22; Br 30.83; N 2.36; S 5.89. C21H23Br2NO2S. Cal-
culated, %: C 49.14; H 4.52; Br 31.13; N 2.73; S 6.25.
6'-H, J = 9.9 Hz). C NMR spectrum, δC, ppm: 18.8,
19.5, 20.1 (CH3); 21.6, 22.8 (CH2); 43.6 (C4a); 71.5
(C9a); 126.4, 127.7, 128.6, 129.3, 130.1, 131.5 (C1, C2,
C6, C7, C2', C6', C3', C5'); 130.4, 131.4, 135.2, 136.3,
141.5, 143.8 (C4b, C5, C8, C8a, C1', C4'). Found, %:
C 71.07; H 6.19; N 3.64; S 8.81. C21H23NO2S. Cal-
culated, %: C 71.40; H 6.56; N 3.90; S 9.07.
Compounds VIII and IX were synthesized in
a similar way.
N-(1,5-Dibromo-8-methoxy-1,2,3,4,4a,9a-hexa-
hydro-9H-carbazol-9-yl)-p-toluenesulfonamide
(VIII) was obtained from 0.5 g (1.15 mmol) of com-
pound V. Yield 0.48 g (81%), mp 129–132°C (from
Compounds XI–XV were synthesized in a similar
1
way.
EtOH). H NMR spectrum, δ, ppm: 1.25–2.30 m (6H,
CH2), 2.40 s (3H, CH3), 3.10 m (1H, 4a-H), 3.65 s (3H,
OCH3), 3.60–3.75 m (1H, 1-H), 4.80 d.d (1H, 9a-H,
J1 = 6.4, J2 = 9.4 Hz), 6.80 d (1H, Harom, J = 8.8 Hz),
7.20 d (1H, Harom, J = 8.8 Hz), 7.30 d (2H, Harom, J =
8.3 Hz), 7.95 d (1H, Harom, J = 8.8 Hz). 13C NMR spec-
trum, δC, ppm: 21.5, 55.7 (CH3); 22.0, 24.0 (C3, C4);
35.7 (C2); 47.4 (C4a); 52.2 (C1); 72.3 (C9a); 108.1,
133.3, 136.1, 137.7, 143.4, 151.6 (C4b, C5, C8, C8a, C1',
C4'); 113.6, 128.1, 128.7, 131.6 (C5, C6, C2', C6', C3',
C5'). Found, %: C 46.32; H 4.18; Br 30.98; N 2.65;
S 6.34. C20H21Br2NO3S. Calculated, %: C 46.62;
H 4.11; Br 31.01; N 2.72; S 6.22.
N-(8-Methoxy-3,4,4a,9a-tetrahydro-9H-carba-
zol-9-yl)-p-toluenesulfonamide (XI) was obtained
from 1.3 g (3 mmol) of compound V. Yield 0.98 g
1
(92%), mp 151–153°C. H NMR spectrum, δ, ppm:
1.65–2.10 m (4H, CH2), 2.40 s (3H, CH3), 3.05 m
(1H, 4a-H), 3.82 s (3H, OCH3), 5.08 d (1H, 9a-H, J =
7.3 Hz), 5.70 d (1H, 1-H, J = 10.3 Hz), 6.68 d (1H,
2-H, J = 7.3 Hz), 6.82 d (1H, 5-H, J = 8.2 Hz), 7.10–
7.28 m (4H, Harom), 7.60 d (2'-H, 5'-H, J = 8.2 Hz).
Found, %: C 67.49; H 5.80; N 4.05; S 9.18.
C20H21NO3S. Calculated, %: C 67.58; H 5.95; N 3.94;
S 9.02.
N-(1,6-Dibromo-8-methyl-1,2,3,4,4a,9a-hexa-
hydro-9H-carbazol-9-yl)-p-toluenesulfonamide (IX)
was obtained from 0.5 g (1.2 mmol) of compound VI;
the reaction was carried out in the dark. Yield 0.19 g
N-(8-Methyl-3,4,4a,9a-tetrahydro-9H-carbazol-
9-yl)-p-toluenesulfonamide (XII) was obtained from
0.4 g (0.8 mmol) of compound VI. Yield 0.285 g
1
(98%), mp 168–170°C (from EtOH). H NMR spec-
1
(32%), mp 203–205°C (from EtOH). H NMR spec-
trum, δ, ppm: 1.60–1.95 m (4H, CH2), 2.40 s (3H,
CH3), 2.60 s (3H, CH3), 2.50–2.62 m (1H, 4a-H),
4.83 d.d.d (1H, 9a-H, J1 = 1.9, J2 = 4.6, J3 = 7.0 Hz),
5.65 d.t (1H, 2-H, J1 = 2.8, J2 = 10.2 Hz), 5.96 d.d (1H,
1-H, J1 = 5.0, J2 = 10.2 Hz), 6.81 d (1H, 5-H, J =
5.6 Hz), 7.05–7.20 m (4H, Harom), 7.41 d (2H, 2'-H,
trum, δ, ppm: 1.52–1.8 m (6H, CH2), 2.43 s and 2.58 s
(3H each, CH3), 2.92 m (1H, 4a-H), 4.42 d.d (1H,
9a-H, J1 = 2.7, J2 = 6.7 Hz), 6.92 d (1H, Harom), 7.22 d
(2H, Harom, J = 8.1 Hz), 7.30 s (1H, Harom), 7.61 d
(2H, Harom, J = 8.1 Hz). Found, %: C 48.32; H 4.18;
Br 31.98; N 2.65; S 6.34. C20H21Br2NO2S. Calculated,
%: C 48.16; H 4.24; Br 32.01; N 2.81; S 6.42.
13
5'-H, J = 8.2 Hz). C NMR spectrum, δC, ppm: 19.1,
21.5 (CH3); 19.8 (C3); 21.8 (C4); 37.6 (C4a); 63.5 (C9a);
120.1 (C8); 120.5, 125.7, 126.3, 130.2, 131.1 (C5, C6',
C7, C1, C2); 127.4 (C6', C2'); 129.3 (C3', C5'); 127.7,
133.3, 135.2, 138.7, 143.7 (C4b, C8, C8a, C1, C4).
Found, %: C 70.91; H 6.12; N 4.45; S 9.36.
C20H21NO2S. Calculated, %: C 70.77; H 6.24; N 4.13;
S 9.44.
N-(5,8-Dimethyl-3,4,4a,9a-tetrahydro-9H-carba-
zol-9-yl)-p-toluenesulfonamide (X). A solution of
0.57 g (1 mmol) of compound IV in 10 ml of piperi-
dine was heated for 6 h at 110°C. When the dehydro-
bromination was complete, the solvent was removed
under reduced pressure, the residue was dissolved in
50 ml of methylene chloride, and the solution was
washed with water (2×20 ml). The organic phase was
dried over Na2SO4, the solvent was removed under
reduced pressure, and crude product X was recrystal-
lized from ethanol. Yield 0.36 g (77.5%), mp 118–
121°C (from EtOH). 1H NMR spectrum, δ, ppm: 1.55–
1.82 m (4H, CH2); 2.11 s, 2.48 s, and 2.50 s (3H each,
CH3); 2.64 m (1H, 4a-H); 4.77 d (1H, 9a-H, J =
7.8 Hz); 5.60 m and 5.78 m (2H, 1-H, 2-H); 6.84 d
(1H, 6-H, J = 7.7 Hz); 7.01 d (1H, 7-H, J = 7.6 Hz);
7.15 d (2H, 3'-H, 5'-H, J = 8.1 Hz), 7.34 d (2H, 2'-H,
N-(6-Bromo-5,8-dimethyl-3,4,4a,9a-tetrahydro-
9H-carbazol-9-yl)-p-toluenesulfonamide (XIII) was
obtained from 0.7 g (2 mmol) of dibromide VII. Yield
1
0.49 g (85%), mp 210–212°C (from EtOH). H NMR
spectrum, δ, ppm: 1.48–1.98 m (4H, CH2); 2.19 s,
2.43 s, and 2.49 s (3H each, CH3); 3.15 m (1H, 4a-H);
4.75 d.t (1H, 9a-H); 5.59 d.t (1H, 2-H, J = 2.0 Hz);
5.80 d.d (1H, 1-H, J1 = 1.3, J2 = 4.0 Hz); 7.18 d (2H,
2'-H, 6'-H, J = 7.5 Hz); 7.27 s (1H, 7-H); 7.35 d (2H,
13
3'-H, 5'-H, J = 7.5 Hz). C NMR spectrum, δC, ppm:
18.4, 18.9, 21.4 (CH3); 19.8, 22.2 (CH2); 39.6 (C4a);
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 43 No. 3 2007

SYNTHESIS OF NEW PARTIALLY HYDROGENATED CARBAZOLES
413
62.9 (C9a); 122.8 (C6); 125.8 (C1); 127.3 (C2); 129.1
(C2', C6'); 131.0 (C8); 131.3 (C3', C5'); 131.7 (C5); 133.5
(C7); 134.5 (C4b); 138.2 (C8a); 140.7 (C1'); 143.9 (C4').
Found, %: C 58.32; H 5.11; Br 18.47; N 3.21; S 7.38.
C21H22BrNO2S. Calculated, %: C 58.34; H 5.13;
Br 18.48; N 3.24; S 7.41.
compound I was added under stirring, and the mixture
was heated for 10 h at 100°C. When the reaction was
complete, the solvent was removed under reduced
pressure, the residue was dissolved in chloroform, the
solution was washed with 100 ml of a 10% solution of
NaHCO3, the organic phase was dried over Na2SO4,
the solvent was removed under reduced pressure, and
the residue was subjected to chromatography in a short
column charged with silica gel using benzene as
eluent. Yield 0.586 g (76.8%), amorphous substance,
N-(5-Bromo-8-methoxy-3,4,4a,9a-tetrahydro-
9H-carbazol-9-yl)-p-toluenesulfonamide (XIV) was
obtained from 0.2 g (0.38 mmol) of compound VIII.
Yield 0.15 g (91%), amorphous substance, Rf 0.72
1
1
Rf 0.6 (C6H6–EtOAc, 9:1). H NMR spectrum, δ, ppm:
(C6H6–EtOAc, 5:1). H NMR spectrum, δ, ppm: 1.30–
1.20–1.62 m (8H, CH2); 2.12 s, 2.43 s, and 2.52 s (3H
each, CH3); 2.63 m (1H, 4a-H); 4.2 m (1H, 9a-H);
6.82 d (1H, 6-H, J = 7.8 Hz); 6.98 d (1H, 7-H, J =
7.8 Hz); 7.16 d (2H, 3'-H, 5'-H, J = 8.1 Hz); 7.41 d
2.30 m (4H, CH2), 2.50 s (3H, CH3), 3.30 m (1H,
4a-H), 3.70 s (3H, OCH3), 5.05 d (1H, 9a-H, J =
6.2 Hz), 5.70–5.95 m (2H, 1-H, 2-H), 6.65 d (1H, 7-H,
J = 8.7 Hz), 7.15 d (1H, 6-H, J = 8.7 Hz), 7.20 d (2H,
3'-H, 5'-H, J = 8.2 Hz), 7.69 d (2H, 2'-H, 6'-H, J =
13
(2H, 2'-H, 6'-H, J = 8.1 Hz). C NMR spectrum, δC,
13
8.2 Hz). C NMR spectrum, δC, ppm: 20.9, 22.6 (C3,
ppm: 19.0, 19.3, 21.3 (CH3); 20.3, 22.6, 24.9, 27.8
(CH2); 40.8 (C4a); 63.9 (C9a); 127.1, 128.7, 129.1, 129.6
(C6, C7, C2', C6', C3', C5'); 130.0, 131.5, 135.8, 136.6,
141.0, 143.5 (C4b, C5, C6, C8, C8a, C1', C4'). Found, %:
C 69.86; H 6.85; N 3.65; S 8.75. C21H25NO2S. Cal-
culated, %: C 70.90; H 7.09; N 3.94; S 9.02.
C4); 21.4 (CH3); 41.7 (C4a); 55.7 (OCH3); 62.3 (C9a);
109.5 (C5); 132.7, 137.3, 137.8, 143.3 (C4b, C8a, C1',
C4'); 150.7 (C8); 113.6 (C7); 125.5, 127.1, 129.1, 130.2,
132.1 (C6, C1, C2, C2', C6', C3', C5'). Found, %: C 55.10;
H 4.50; Br 18.34; N 3.45; S 7.45. C20H20BrNO3S. Cal-
culated, %: C 55.31; H 4.64; Br 18.40; N 3.22; S 7.38.
REFERENCES
N-(6-Bromo-8-methyl-3,4,4a,9a-tetrahydro-9H-
carbazol-9-yl)-p-toluenesulfonamide (XV) was ob-
tained from 0.12 g (0.2 mmol) of dibromo derivative
IX. Yield 0.06 g (71%), mp 161–163°C (from EtOH).
1H NMR spectrum, δ, ppm: 1.50–2.00 m (4H, CH2),
2.40 s (3H, CH3), 2.51 s (3H, CH3), 2.52–2.61 m (1H,
4a-H), 4.70 d.d.d (1H, 9a-H, J1 = 2.0, J2 = 4.6, J3 =
7.0 Hz), 5.60 m (1H, 2-H), 5.57 m (1H, 1-H), 6.94 s
(1H, Harom), 7.20 d (2H, Harom, J = 8.3 Hz), 7.25 s (1H,
1. Miller, R.B. and Moock, T., Tetrahedron Lett., 1980,
vol. 21, p. 3319.
2. Gribble, G.W. and Saulnier, M.G., Heterocycles, 1985,
vol. 23, p. 1277.
3. Raposo, M.M., Pereira, A.M.B., Oliveira-Campos, A.M.F.,
and Shannon, P.V.R., J. Chem. Res., Synop., 1999, p. 466.
4. Abdrakhmanov, I.B., Sharafutdinov, V.M., and Tolsti-
kov, G.A., Izv. Akad. Nauk SSSR, Ser. Khim., 1982,
p. 2160.
H
arom), 7.45 d (2H, Harom, J = 8.3 Hz). Found, %:
5. Mustafin, A.G., Khalilov, I.N., Sharafutdinov, V.M.,
D’yachenko, D.I., Abdrakhmanov, I.B., and Tolsti-
kov, G.A., Izv. Ross. Akad. Nauk, Ser. Khim., 1997,
p. 630; Mustafin, A.G., Khalilov, I.N., Abdrakhma-
nov, I.B., and Tolstikov, G.A., Khim. Prirodn. Soedin.,
1989, vol. 6, p. 818.
6. Pretsch, E., Clerk, T., Seible, J., and Simon, W., Tables of
Spectral Data for Structure Determination of Organic
Compounds, Berlin: Springer, 1983.
C 57.10; H 4.50; Br 18.94; N 3.45; S 7.45.
C20H20BrNO2S. Calculated, %: C 57.42; H 4.82;
Br 19.10; N 3.35; S 7.66.
N-(5,8-Dimethyl-1,2,3,4,4a,9a-hexahydro-9H-car-
bazol-9-yl)-p-toluenesulfonamide (XVI). N-Methyl-
N-phenylformamide, 0.29 g (2 mmol), and phosphoryl
chloride, 0.274 ml (2 mmol), were dissolved in 10 ml
of dichlorobenzene on heating, 0.763 g (2 mmol) of
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 43 No. 3 2007