PAPER
3-Acyl-2-(alkylsulfanyl)indoles and Related Compounds
1789
Hz, 1 H), 7.21 (d, J = 8.7 Hz, 1 H), 7.57 (d, J = 2.8 Hz, 1 H), 8.37
(s, 1 H).
Anal. Calcd for C14H17NO3S: C, 60.19; H, 6.13; N, 5.01; Found: C,
60.09; H, 6.28; N, 4.93.
13C NMR (125 MHz, CDCl3): d = 14.60, 14.88, 55.69, 59.85,
102.96, 105.49, 111.01, 111.94, 128.42, 130.79, 142.72, 155.76,
165.36.
3,4-Dihydro-2H-[1,3]thiazino[3,2-a]indol-10-yl)(phenyl)metha-
none (6a)
Pale-yellow solid; mp 196–197 °C (hexane–CH2Cl2).
IR (KBr): 1603 cm–1.
1H NMR (500 MHz, CDCl3): d = 2.51 (quint, J = 6.5 Hz, 2 H), 3.12
(t, J = 6.5 Hz, 2 H), 4.23 (t, J = 6.5 Hz, 2 H), 7.03 (ddd, J = 8.2, 7.3,
1.4 Hz, 1 H), 7.07 (d, J = 8.2 Hz, 1 H), 7.16 (dd, J = 8.2, 7.3, 1.4 Hz,
1 H), 7.26 (d, J = 8.2 Hz, 1 H), 7.46 (t, J = 7.3 Hz, 2 H), 7.54 (t, J =
7.3 Hz, 1 H), 7.72 (d, J = 7.3 Hz, 2 H).
13C NMR (125 MHz, CDCl3): d = 22.76, 34.20, 42.07, 108.16,
119.83, 121.51, 121.91, 125.49, 126.12, 128.16, 128.38, 130.85,
138.21, 141.22, 143.17, 190.45.
MS (EI, 70 eV): m/z (%) = 265 (100) [M+].
Anal. Calcd for C13H15NO3S: C, 58.85; H, 5.70; N, 5.28. Found: C,
58.82; H, 5.70; N, 5.28.
Ethyl 6-Methyl-2-(methylsulfanyl)-1H-indole-3-carboxylate
(4g)
White solid; mp 125–126 °C (hexane–Et2O).
IR (KBr): 3331, 1655 cm–1.
1H NMR (500 MHz, CDCl3): d = 1.45 (t, J = 7.3 Hz, 3 H), 2.44 (s,
3 H), 2.62 (s, 3 H), 4.91 (q, J = 7.3 Hz, 2 H), 7.05 (dd, J = 8.2, 0.9
Hz, 1 H), 7.12 (d, J = 0.9 Hz, 1 H), 7.91 (d, J = 8.2 Hz, 1 H), 8.37
(s, 1 H).
13C NMR (125 MHz, CDCl3): d = 14.59, 15.01, 21.56, 59.80,
105.74, 110.37, 120.33, 123.62, 125.16, 132.21, 136.16, 141.70,
165.36.
MS (EI, 70 eV): m/z (%) = 293 (100, [M+]).
Anal. Calcd for C18H15NOS: C, 73.69; H, 5.15; N, 4.77; Found: C,
73.69; H, 5.28; N, 4.63.
1-(8-Chloro-3,4-dihydro-2H-[1,3]thiazino[3,2-a]indol-10-
yl)propan-1-one (6b)
Pale-yellow solid; mp 135–137 °C (hexane–CHCl3).
IR (KBr): 1622 cm–1.
Anal. Calcd for C13H15NO2S: C, 62.62; H, 6.06; N, 5.62; Found: C,
62.42; H, 6.10; N, 5.72.
1-[1-Methyl-2-(methylsulfanyl)-1H-indol-3-yl](phenyl)metha-
none (5a); Typical Procedure
1H NMR (500 MHz, CDCl3): d = 1.28 (t, J = 7.3 Hz, 3 H), 2.45
(quint, J = 5.5 Hz, 2 H), 2.96 (q, J = 7.3 Hz, 2 H), 3.08 (t, J = 5.5
Hz, 2 H), 4.15 (t, J = 5.5 Hz, 2 H), 7.16–7.19 (m, 2 H), 7.80 (d,
J = 1.4 Hz, 1 H).
13C NMR (125 MHz, CDCl3): d = 7.86, 22.54, 24.86, 35.20, 42.09,
109.15, 112.80, 119.15, 121.37, 126.38, 128.20, 136.68, 143.15,
195.12.
A mixture of 1b (0.10 g, 0.45 mmol), Et3N (0.11 g, 1.1 mmol), sul-
fur (17 mg, 0.54 mmol), and selenium (1.1 mg, 14 mmol) in THF (3
mL) was stirred at r.t. After 1.5 h, NaH (60% in oil; 43 mg, 1.1
mmol) was added, and the mixture was stirred for an additional 30
min at r.t. DMSO (1.5 mL) and MeI (0.15 g, 1.1 mmol) were added,
and the resulting mixture was stirred overnight. Sat. aq NH4Cl (10
mL) was added and the organic materials were extracted with
EtOAc (3 × 10 mL). The combined extracts were washed with
brine, dried (anhyd Na2SO4), and concentrated to give a residue that
was purified by preparative TLC (silica gel) to give 5a as a yellow
oil; yield: 89 mg (70%); Rf = 0.27 (benzene).
MS (EI, 70 eV): m/z (%) = 279 (38) [M+], 250 (100).
Anal. Calcd for C14H14ClNOS: C, 60.10; H, 5.04; N, 5.01; Found:
C, 60.28; H, 4.93; N, 4.82.
Ethyl 6-Methyl-2,3-dihydro[1,3]thiazolo[3,2-a]indole-9-car-
boxylate (6c)
Beige solid; mp 107–109 °C (hexane–Et2O).
IR (KBr): 1682 cm–1.
1H NMR (500 MHz, CDCl3): d = 1.42 (t, J = 7.3 Hz, 3 H), 2.45 (s,
3 H), 3.82 (t, J = 7.3 Hz, 2 H), 4.27 (t, J = 7.3 Hz, 2 H), 4.37 (q,
J = 7.3 Hz, 2 H), 6.97 (s, 1 H), 7.02 (d, J = 8.2 Hz, 1 H), 7.85 (d,
J = 8.2 Hz, 1 H).
13C NMR (125 MHz, CDCl3): d = 14.62, 21.61, 34.89, 45.49, 59.69,
100.12, 109.41, 120.24, 123.21 (2 C), 128.57, 131.66, 134.78,
164.84.
IR (neat): 1634, 1599 cm–1.
1H NMR (400 MHz, CDCl3): d = 2.37 (s, 3 H), 3.95 (s, 3 H), 7.14
(ddd, J = 8.4, 7.3, 1.1 Hz, 1 H), 7.30 (ddd, J = 8.4, 7.3, 1.1 Hz, 1 H),
7.37 (d, J = 8.4 Hz, 1 H), 7.45 (t, J = 7.3 Hz, 2 H), 7.48 (d, J = 8.4
Hz, 1 H), 7.56 (tt, J = 7.3, 1.5 Hz, 1 H), 7.82 (dd, J = 7.3, 1.5 Hz, 2
H).
13C NMR (125 MHz, CDCl3): d = 1.00, 20.21, 30.42, 109.81,
119.55, 121.16, 121.72, 123.43, 127.04, 128.07, 129.52, 131.96,
137.35, 140.46, 192.33.
MS (EI, 70 eV): m/z (%) = 281 (100) [M+].
MS (EI, 70 eV): m/z (%) = 261 (100) [M+].
Anal. Calcd for C17H15NOS: C, 72.57; H, 5.37; N, 4.98; Found: C,
72.77; H, 5.49; N, 4.91.
Anal. Calcd for C14H15NO2S: C, 64.34; H, 5.79; N, 5.36. Found: C,
64.28; H, 5.93; N, 5.32.
Ethyl 5-Methoxy-1-methyl-2-(methylsulfanyl)-1H-indole-3-
carboxylate (5b)
White solid; mp 82–83 °C (hexane–Et2O).
IR (KBr): 1686, 1616 cm–1.
1H NMR (500 MHz, CDCl3): d = 1.48 (t, J = 7.3 Hz, 3 H), 2.51 (s,
3 H), 3.89 (s, 3 H), 3.90 (s, 3 H), 4.45 (q, J = 7.3 Hz, 2 H), 6.96 (dd,
J = 8.7, 2.3 Hz, 1 H), 7.23 (d, J = 8.7 Hz, 1 H), 7.67 (d, J = 2.3 Hz,
1 H).
13C NMR (125 MHz, CDCl3): d = 14.53, 19.53, 30.56, 55.67, 59.73,
103.26, 109.74, 110.72, 113.81, 127.39, 132.38, 140.14, 155.86,
164.68.
Ethyl 7-Methyl-3,4-dihydro-2H-[1,3]thiazino[3,2-a]indole-10-
carboxylate (6d)
Yellow solid; mp 137–139 °C (hexane–CH2Cl2).
IR (KBr): 1667 cm–1.
1H NMR (500 MHz, CDCl3): d = 1.43 (t, J = 7.3 Hz, 3 H), 2.40
(quint, J = 6.0 Hz, 2 H), 2.46 (s, 3 H), 3.07 (t, J = 6.0 Hz, 2 H), 4.01
(t, J = 6.0 Hz, 2 H), 4.39 (q, J = 7.3 Hz, 2 H), 7.00 (s, 1 H), 7.04 (d,
J = 7.8 Hz, 1 H), 7.87 (d, J = 7.8 Hz, 1 H).
13C NMR (125 MHz, CDCl3): d = 14.64, 21.68, 23.05, 24.79, 41.89,
59.49, 102.98, 108.09, 119.83, 123.54, 123.92, 131.17, 138.13,
139.47, 165.38.
MS (EI, 70 eV): m/z (%) = 279 (100) [M+].
Synthesis 2009, No. 11, 1786–1790 © Thieme Stuttgart · New York