Arkivoc 2018, v, 0-0
Perni, R. B. et al.
(ether/benzene, 1:1), stored at 0 °C overnight, and the resulting crystals were collected. This cooling
procedure was repeated twice to give 33.9 g (48%) of 3, which was usually used without further purification.
4
The product was recrystallized from ether to give 3, mp 47–51 °C (lit. mp 47–50 °C); IR (CHCl ) 1720 (s), 1670
3
-
1
1
13
(
s) cm ; H NMR (CDCl ) 1.50 (s, 3H), 1.70–3.00 (m, 10H), 5.92 (s, 1H); C NMR (CDCl ) 22.6, 22.9, 29.4,
3
3
3
4
1.4, 33.3, 37.3, 50.3, 125.4, 165.4, 197.6, 210.4.
a-Methyl-4,4a,7,8-tetrahydro-3H-spiro[naphthalene-2,2'-[1,3]dithiolan]-5(6H)-one (4). To a magnetically
5
stirred solution of 3 (20.0 g, 0.11 mol) and 1,2-ethanedithiol (9.40 mL, 0.11 mol) in dry ether (150 mL) was
added boron trifluoride etherate (1.0 mL). Stirring was continued overnight at room temperature. The
reaction mixture was poured into water (200 mL) and the layers were separated. The aqueous portion was
extracted with ether (2 x 50 mL) and the combined organic portions were washed with saturated sodium
bicarbonate solution (1 x 100 mL), water (1 x 100 mL), and dried over sodium sulfate. Concentration in vacuo
afforded 23.3 g (82%) of crude product as yellow crystals. Recrystallization from ether afforded 15.2 g (53%)
5
of 4, mp 116–118 °C (lit. mp 123–124 °C); IR (KBr) 2920 (m), 1694 (s), 1416 (m), 1230 (m), 1014 (m), 820 (m)
-
1 1
cm ; H NMR (CDCl ) 1.29 (s, 3H), 1.40–2.80 (m, 10H), 3.31 (s, 4H), 5.68 (br s, 1H).
3
4
a-Methyl-4,4a,7,8-tetrahydro-3H-spiro[naphthalene-2,2'-[1,3]dithian]-5(6H)-one (5). The same procedure
as for the preparation of 4 afforded 5 (64%) as a colorless oil following chromatography on Florisil (Et O). This
2
oil crystallized on standing at 0 °C overnight. Recrystallization from ether (2X) gave analytically pure material,
-
1 1
mp 98–99.5 °C; IR (CHCl ) 2950 (s), 1708 (s), 1665 (m), 1420 (m), 1200 (m) cm ; H NMR (CDCl ) 1.28 (s, 3H),
3
3
13
1
4
7
1
.40–3.20 (m, 16H), 5.57 (s, 1H) ppm; C NMR (CDCl ) 24.6, 24.8, 25.0, 26.4, 26.8, 27.8, 31.0, 32.5, 37.8,
8.2, 50.6, 125.2, 143.4, 212.2 ppm. Anal. Calcd for C H OS : C, 62.64; H, 7.51; S, 23.89. Found: C, 62.35; H,
.58; S, 23.95.
1b-Methyl-1,2,5,6,11,11b-hexahydrospiro[benzo[a]carbazole-3,2'-[1,3]dithiolane] (6). To glacial acetic acid
3
1
4
20
2
(100 mL) at room temperature was added 4 (5.00 g, 19.6 mmol) and commercial (Pfaltz & Bauer)
phenylhydrazine hydrochloride (2.84 g, 19.6 mmol). The mixture was magnetically stirred and the
temperature was brought to 100 °C and maintained for 2 h. As the temperature was raised the solids
gradually went into solution. The solution was allowed to cool to room temperature, poured into distilled
water (100 mL), and placed in the refrigerator for 30 min. The resultant precipitate was suction filtered, dried
in vacuo, and chromatographed on a Florisil column with benzene. Only one 250 mL fraction was collected.
The benzene solution was concentrated to one-half its volume in vacuo, hexane (125 mL) was added, and the
mixture was placed in the refrigerator for several hours. The product was then collected by suction filtration
to afford 4.57 g (71%) of 6 as a fluffy white powder, mp 216–217 °C; IR (CHCl ) 3500 (s), 3020 (m), 2945 (s),
3
-
1 1
2
3
4
770 (m), 1478 (s), 1310 (m), 1303 (m), 1246 (m) cm ; H NMR (CDCl ) 1.41 (s, 3H), 1.75–3.05 (m, 8H), 3.10–
.50 (m, 4H), 5.71 (s, 1H), 7.00–7.80 (m, 5H) ppm; C NMR (CDCl ) 22.5, 26.7, 29.9, 34.9, 35.5, 38.1, 39.5,
0.3, 65.0, 108.5, 110.5, 118.1, 119.3, 121.3, 126.3, 127.1, 136.1, 140.6, 142.3 ppm; UV max
nm; MS (70 eV) m/e 327 (34% M ), 312 (28%), 252 (24%), 219 (100%), 109 (39%). Anal. Calcd for C H NS : C,
3
1
3
3
EtOH
227, 278, 292
+
1
9
21
2
6
1
9.68; H, 6.46; N, 4.28; S, 19.58. Found: C, 69.78; H, 6.51; N, 4.28; S, 19.53.
1b-Methyl-1,2,5,6,11,11b-hexahydrospiro[benzo[a]carbazole-3,2'-[1,3]dithiane (7). The same procedure as
for the preparation of 6 afforded 41% of 7 as a yellow solid following chromatography on Florisil (benzene).
Recrystallization from benzene (2X) gave analytically pure material, mp 235–237 °C; IR (KBr) 3330 (s), 2910 (s),
-
1 1
1
1
1
461 (s), 1440 (s), 860 (s), 725 (s) cm ; H NMR (CDCl /DMSO ) 1.49 (s, 3H), 1.65–3.40 (m, 14H), 5.62 (s,
3
d6
1
3
H), 6.90–7.45 (m, 5H) ppm; C NMR (DMSO ) 22.4, 24.5, 25.5, 26.2, 26.4, 29.5, 31.9, 32.6, 35.8, 48.2,
06.1, 110.7, 117.5, 118.1, 120.3, 123.3, 126.3, 136.2, 141.2, 144.7 ppm; UV
m/e 342 (6% M ), 220 (18%), 145 (100%), 78 (48%). Anal. Calcd for C H NS : C, 70.33; H, 6.79; N, 4.10; S,
d6
EtOH
228, 281 nm; MS (70 eV)
max
+
2
0
23
2
1
8.78. Found: C, 70.29; H, 6.83; N, 4.06; S, 18.71.
©
Page 6
ARKAT USA, Inc