PAPER
Electrophilic Thiocyanation of Aromatics
963
3-Thiocyanato-1H-indole (2a)
Solid; mp 125–127 °C.
13C NMR (50 MHz, CDCl3): d = 108.2, 110.4, 111.3, 115.9, 126.8,
129.1, 131.3, 133.5, 147.1, 174.2.
IR (KBr): 3341, 3107, 2924, 2853, 2157, 1618, 1503, 1455, 1217,
758, 668, 589 cm–1.
EIMS: m/z (%) = 204 (M+, 10), 179 (6), 176 (36), 142 (10), 118
(42), 92 (6), 69 (8), 57 (20), 43 (20).
1H NMR (200 MHz, CDCl3): d = 7.23–7.45 (m, 4 H), 7.80 (d, 1 H,
J = 8.0 Hz), 8.60 (br s, 1 H, NH).
HRMS: m/z calcd for C10H8N2OS: 204.0357; found: 204.0359.
1-Benzyl-5-thiocyanato-2-indolinone (2g)
Solid; mp 210–211 °C.
EIMS: m/z (%): 174 (M+, 30), 155 (25), 141 (30), 97 (20), 85 (27),
71 (36), 57 (94), 43 (100).
IR (KBr): 3422, 2923, 2853, 2126, 1719, 1654, 1466, 1364, 1321,
1220, 1026, 824, 769, 629 cm–1.
2-Methyl-3-thiocyanato-1H-indole (2b)
Solid; mp 102–103 °C.
1H NMR (200 MHz, CDCl3): d = 2.90 (s, 2 H), 3.80 (s, 2 H), 6.90
(d, J = 8.4 Hz, 1 H), 7.40–7.65 (m, 8 H).
EIMS: m/z (%) = 280 (M+, 30), 199 (10), 84 (70), 66 (100), 46 (20).
IR (KBr): 3324, 2933, 2151, 1618, 1543, 1408, 1229, 740, 651
cm–1.
1H NMR (200 MHz, CDCl3): d = 2.48 (s, 3 H), 7.15–7.40 (m, 3 H),
7.70 (d, J = 8.1 Hz, 1 H), 8.48 (br s, 1 H, NH).
5-Thiocyanato-2,3-indolinedione (2h)
Solid; mp 203–204 °C.
IR (KBr): 3447, 2924, 2165, 1618, 1460, 771 cm–1.
EIMS: m/z (%) = 188 (M+, 100), 156 (18), 77 (14).
5-Methoxy-3-thiocyanato-1H-indole (2c)
Solid; mp 122–123 °C.
1H NMR (200 MHz, DMSO-d6): d = 7.05 (d, J = 8.1 Hz, 1 H), 7.65–
7.75 (m, 2 H) 11.35 (br s, 1 H, NH).
IR (KBr): 3375, 2983, 2155, 1687, 1385, 1459, 1291, 1035, 780
cm–1.
1H NMR (300 MHz, CDCl3): d = 3.90 (s, 3 H), 6.80 (dd, J = 8.5, 0.8
Hz, 1 H), 7.10 (d, J = 1.8 Hz, 1 H), 7.30 (d, J = 8.5 Hz, 1 H), 7.50
(d, J = 0.8 Hz, 1 H), 8.50 (br s, 1 H, NH).
EIMS: m/z (%) = 204 (M+, 20), 180 (80), 176 (35), 135 (30), 109
(10), 88 (100), 71 (60). 43 (50).
HRMS: m/z calcd for C9H4N2O2S: 203.9993; found: 203.9992.
4-Thiocyanatoaniline (2i)
Solid; mp 49–51 °C.
EIMS: m/z (%) = 204 (M+, 100), 178 (15), 149 (20), 122 (40), 107
(65), 47 (60).
IR (KBr): 3345, 2923, 2143, 1635, 1593, 1390, 1297, 1176, 821
cm–1.
1H NMR (200 MHz, CDCl3): d = 3.90 (br s, 2 H, NH2), 6.60 (d,
J = 8.1 Hz, 2 H), 7.45 (d, J = 8.1 Hz, 2 H).
1-Ethyl-2-phenyl-1H-3-indolyl Thiocyanate (2d)
Solid; mp 107–109 °C.
IR (KBr): 2969, 2359, 2341, 2149, 1458, 1467, 1445, 1390, 1340,
1198, 1074, 804, 770, 746, 700, 482 cm–1.
EIMS: m/z (%) = 150 (M+, 100), 125 (70), 91 (80), 76 (20).
1H NMR (200 MHz, CDCl3): d = 1.28 (t, J = 7.1 Hz, 3 H), 4.13 (q,
J = 7.1 Hz, 2 H), 7.22–7.80 (m, 9 H).
13C NMR (50 MHz, CDCl3): d = 15.4, 39.8, 110.6, 119.1, 121.9,
123.5, 128.8, 129.5, 129.7, 130.5, 136.0, 146.1.
EIMS: m/z (%) = 278 (M+, 100), 264 (6), 250 (20), 237 (10), 224
(6).
2-Chloro-3-methyl-4-thiocyanatoaniline (2j)
Solid; mp 112–113 °C.
IR (KBr): 3382, 2148, 1632, 1578, 1461, 1394, 1302, 1109, 811,
593 cm–1.
1H NMR (200 MHz, CDCl3): d = 2.45 (s, 3 H), 3.85 (br s, 2 H, NH2),
6.60 (d, J = 8.2 Hz, 1H), 7.35 (d, J = 8.2 Hz, 1H).
HRMS: m/z calcd for C17H14N2S: 278.0877; found: 278.0899.
13C NMR (50 MHz, CDCl3): d = 14.5, 114.0, 121.9, 131.5, 147.9.
EIMS: m/z (%) = 200 (M + + 2, 40), 198 (M+, 100), 163 (55), 136
(20), 119 (15) 104 (15), 77 (23), 51 (15).
1-Benzyl-1H-3-indolyl Thiocyanate (2e)
Solid; mp 82–84 °C.
HRMS: m/z calcd for C8H7N2ClS: 198.0018; found: 198.0009.
IR (KBr): 3068, 2947, 2832, 2359, 2341, 2163, 1506, 1453, 1440,
1157, 732, 693 cm–1.
1H NMR (200 MHz CDCl3): d = 5.25 (s, 2 H), 7.35 (s, 1 H), 7.78 (d,
J = 6.7 Hz, 1 H), 7.08 (d, J = 6.7 Hz, 2 H), 7.17–7.36 (m, 6 H).
13C NMR (50 MHz, CDCl3): d = 91.6, 111.3, 119.2, 121.8, 123.9,
127.2, 128.1, 128.8, 129.4, 134.3, 135.9, 136.9.
N,N-Dimethyl-4-thiocyanatoaniline (2k)
Solid; mp 72–74 °C.
IR (KBr): 3382, 3094, 2978, 2843, 2158, 1685, 1461, 1295, 1040,
765 cm–1.
1H NMR (300 MHz, CDCl3): d = 3.02 (s, 6 H), 6.60 (d, 2 H, J = 8.4
Hz), 7.40 (d, 2 H, J = 8.4 Hz).
EIMS: m/z (%) = 178 (M+, 100), 153 (15), 140 (25), 92 (30), 47
(65).
EIMS: m/z (%) = 264 (M+, 69), 173 (6), 146 (10), 120 (8), 91 (100),
77 (8), 65 (74), 39 (30).
HRMS: m/z calcd for C16H12N2S: 264.0721; found: 264.0712.
1-Methyl-5-thiocyanato-2-indolinone (2f)
Solid; mp 127–129 °C.
N-Ethyl-4-thiocyanatoaniline (2l)
Solid; mp 52–53 °C.
IR (KBr): 3074, 2953, 2924, 2359, 2151, 1726, 1695, 1605, 1493,
1364, 1345, 1106, 1060, 943, 908, 829, 716, 668 cm–1.
1H NMR (200 MHz, CDCl3): d = 3.2 (s, 2 H), 3.53 (s, 2 H), 6.81–
6.85 (d, J = 8.3 Hz, 1 H), 7.44–7.47 (d, J = 8.3 Hz, 1 H), 7.46 (s, 1
IR (KBr): 3388, 2971, 2153, 1595, 1509, 1406, 1329, 1220, 1150,
816, 770, 524 cm–1.
1H NMR (200 MHz, CDCl3): d = 1.29 (t, J = 7.0 Hz, 3 H), 3.25 (q,
J = 7.0 Hz, 2 H), 3.84 (br s, 1 H, NH), 6.60 (d, J = 8.3 Hz, 2 H), 7.45
(d, J = 8.3 Hz, 2 H).
H).
Synthesis 2005, No. 6, 961–964 © Thieme Stuttgart · New York