PAPER
Synthesis of N-Unsubstituted b-Enamino Thioesters
3199
1H NMR (400 MHz, CDCl3): d = 7.61–7.58 (m, 2 Harom), 7.54–7.51
(m, 2 Harom), 7.33–7.30 (m, 3 Harom), 7.22–7.19 (m, 2 Harom), 6.12
(dd, J = 4.8, 9.9 Hz, 1 H), 3.76 (dd, J = 9.9, 17.6 Hz, 1 H), 3.32 (dd,
J = 4.8, 17.6 Hz, 1 H), 2.38 (s, 3 H).
GC-MS (70 eV): m/z (%) = 323 (M+, 1), 304 (6), 215 (11), 214
(100), 213 (11), 212 (13), 186 (37), 172 (3), 166 (7), 159 (7), 145
(47), 135 (5), 125 (5), 117 (6), 111 (8), 110 (100), 109 (27), 95 (8),
75 (6), 65 (10), 51 (5).
13C NMR (100 MHz, CDCl3): d = 157.3, 140.8, 132.8, 132.7, 129.4,
129.0, 128.0, 126.7, 125.8, 87.3, 41.9, 21.5.
Anal. Calcd for C16H12F3NOS: C, 59.43; H, 3.74; N, 4.33. Found:
C, 59.40; H, 3.49; N, 4.35.
GC-MS (70 eV): m/z (%) = 269 (M+, 0.7), 161 (11), 160 (100), 159
(22), 158 (19), 132 (28), 130 (12), 117 (8), 110 (25), 109 (15), 105
(13), 91 (32), 77 (7), 65 (17).
3-(4-Fluorophenyl)-5-(phenylthio)-2-isoxazoline (6f)
Yield: 60%; white crystals; mp 137.0–138.0 °C (Et2O).
FT-IR (KBr): 3054, 2967, 2921, 2847, 1607, 1583, 1514, 1482,
1438, 1358, 1298, 1228, 1159, 1101, 1025, 911, 885, 836, 739, 691
cm–1.
Anal. Calcd for C16H15NOS: C, 71.34; H, 5.61; N, 5.20. Found: C,
71.08; H, 5.83; N, 4.84.
3-(4-Methoxyphenyl)-5-(phenylthio)-2-isoxazoline (6c)
Yield: 90%; yellow powder; mp 117.1–118.0 °C (Et2O).
1H NMR (400 MHz, CDCl3): d = 7.65–7.58 (m, 4 Harom), 7.36–7.30
(m, 3 Harom), 7.12–7.07 (m, 2 Harom), 6.14 (dd, J = 5.1, 10.0 Hz, 1 H),
3.77 (dd, J = 10.0, 17.6 Hz, 1 H), 3.31 (dd, J = 5.1, 17.6 Hz, 1 H).
FT-IR (KBr): 3046, 3004, 2948, 2932, 2838, 1605, 1592, 1582,
1511, 1479, 1458, 1432, 1360, 1254, 1173, 1112, 1091, 1024, 912,
875, 827, 744, 691 cm–1.
1H NMR (400 MHz, CDCl3): d = 7.61–7.56 (m, 4 Harom), 7.34–7.28
(m, 3 Harom), 6.92–6.90 (m, 2 Harom), 6.11 (dd, J = 4.7, 9.9 Hz, 1 H),
3.83 (s, 3 H), 3.75 (dd, J = 9.9, 17.6 Hz, 1 H), 3.32 (dd, J = 4.7, 17.6
Hz, 1 H).
13C NMR (100 MHz, CDCl3): d = 163.9 [d, 1J (19F,13C) = 251 Hz],
156.3, 132.8, 132.5, 129.0, 128.7 [d, 3J (19F,13C) = 8.4 Hz], 128.2,
2
124.90 [d, 4J (19F,13C) = 3.8 Hz], 115.9 [d, J (19F,13C) = 22.1 Hz],
87.6, 41.8.
19F NMR (376 MHz, CDCl3): d = –113.5 (m).
GC-MS (70 eV): m/z (%) = 273 (M+, 1.3), 165 (12), 164 (100), 136
(33), 135 (11), 121 (6), 110 (56), 109 (38), 95 (30), 77 (5), 75 (12),
65 (9), 77 (5).
13C NMR (100 MHz, CDCl3): d = 161.3, 156.9, 132.8, 132.6, 129.0,
128.3, 128.0, 121.2, 114.1, 87.3, 55.3, 42.1.
GC-MS (70 eV): m/z (%) = 285 (M+, 1.1), 176 (54), 175 (100), 174
(26), 160 (13), 148 (10), 147 (20), 146 (24), 133 (12), 132 (44), 121
(25), 110 (67), 109 (24), 92 (13), 84 (11), 77 (33), 76 (11), 66 (16),
51 (13).
Anal. Calcd for C15H12FNOS: C, 65.91; H, 4.43; N, 5.12. Found: C,
65.40; H, 4.49; N, 5.35.
3-(2-Chlorophenyl)-5-(phenylthio)-2-isoxazoline (6g)
Yield: 56%; yellow solid; mp 33.2–34.9 °C (hexane–Et2O).
Anal. Calcd for C16H15NO2S: C, 67.34; H, 5.30; N, 4.91. Found: C,
67.80; H, 5.49; N, 4.54.
FT-IR (KBr): 3059, 2925, 2853, 1584, 1475, 1437, 1347, 1266,
1245, 1231, 1126, 1078, 1038, 959, 907, 835, 752, 692 cm–1.
3-(4-Chlorophenyl)-5-(phenylthio)-2-isoxazoline (6d)
Yield: 65%; yellow crystals; mp 138–139 °C (Et2O).
1H NMR (500 MHz, CDCl3): d = 7.56–7.53 (m, 2Harom), 7.46–7.44
(m, 1 Harom), 7.34–7.32 (m, 1 Harom), 7.29–7.26 (m, 4 Harom), 7.25–
7.18 (m, 1 Harom), 6.09 (dd, J = 4.8, 10.1 Hz, 1 H), 3.93 (dd,
J = 18.2, 10.1 Hz, 1 H), 3.39 (dd, J = 4.8, 18.2 Hz, 1 H).
FT-IR (KBr): 3053, 2977, 2941, 1596, 1582, 1481, 1439, 1402,
1350, 1092, 911, 883, 831, 739, 690, 536 cm–1.
1H NMR (400 MHz, CDCl3): d = 7.60–7.54 (m, 4 H), 7.38–7.29 (m,
5 H), 6.13 (dd, J = 4.8, 10.0 Hz, 1 H), 3.75 (dd, J = 10.0, 17.6 Hz, 1
H), 3.29 (dd, J = 4.8, 17.6 Hz, 1 H).
13C NMR (100 MHz, CDCl3): d = 156.3, 136.4, 132.8, 132.3,
129.05, 129.02, 128.2, 128.0, 127.2, 87.7, 41.6.
13C NMR (100 MHz, CDCl3): d = 157.2, 133.1, 132.8, 132.3, 131.2,
130.6, 130.5, 129.1, 128.24, 128.2, 127.0, 88.1, 44.0.
GC-MS (70 eV): m/z (%) = 289 (M+, 0.6), 182 (33), 181 (13), 180
(100), 178 (10), 154 (14), 152 (42), 111 (25), 110 (30), 109 (19), 75
(12).
GC-MS (70 eV): m/z (%) = 289 (M+, 0.1), 182 (26), 180 (82), 154
(8), 152 (28), 139 (7), 137 (19), 127 (3), 125 (12), 113 (12), 111
(43), 110 (100), 77 (11), 75 (27), 51 (13).
Anal. Calcd for C15H12ClNOS: C, 62.17; H, 4.17; N, 4.83. Found:
C, 62.40; H, 4.25; N, 4.75.
5-(Phenylthio)-3-[4-(trifluoromethyl)phenyl]-2-isoxazoline (6h)
Yield: 56%; yellow oil.
Anal. Calcd for C15H12ClNOS: C, 62.17; H, 4.17; N, 4.83. Found:
C, 62.47; H, 4.70; N, 4.51.
FT-IR (neat): 3063, 2920, 2853, 1603, 1583, 1482, 1440, 1428,
1339, 1316, 1271, 1175, 1128, 1075, 1036, 959, 907, 887, 870, 837,
770, 750, 692 cm–1.
5-(Phenylthio)-3-[4-(trifluoromethyl)phenyl]-2-isoxazoline (6e)
Yield: 71%; white crystals; mp 158.0–159.0 °C (Et2O).
FT-IR (KBr): 3058, 2964, 2925, 2849, 1618, 1599, 1584, 1484,
1441, 1413, 1327, 1166, 1112, 1071, 1027, 1013, 892, 834, 742,
691, 599 cm–1.
1H NMR (400 MHz, CDCl3): d = 7.73 (d, J = 8.4 Hz, 2 Harom), 7.66
(d, J = 8.4 Hz, 2 Harom), 7.61–7.58 (m, 2 Harom), 7.37–7.31 (m, 3
1H NMR (400 MHz, CDCl3): d = 7.73–7.70 (m, 1 Harom), 7.64–7.60
(m, 2 Harom), 7.55–7.51 (m, 2 Harom), 7.37–7.32 (m, 3 Harom), 7.30–
7.26 (m, 1 Harom), 6.15 (dd, J = 4.9, 10.2 Hz, 1 H), 3.84 (dd,
J = 18.2, 10.2 Hz, 1 H), 3.27 (dd, J = 4.9, 18.2 Hz, 1 H).
13C NMR (100 MHz, CDCl3): d = 156.8, 133.0, 132.0, 131.9 [q, 4J
Harom), 6.17 (dd, J = 10.3, 5.1 Hz 1 H), 3.80 (dd, J = 10.3, 17.6 Hz,
(19F,13C) = 1.1 Hz], 130.5, 129.8, 128.9, 128.2 [q, 2J
4
1 H), 3.34 (dd, J = 5.1, 17.6 Hz, 1 H).
(19F,13C) = 31.4 Hz], 128.1, 127.6 [q, J (19F,13C) = 2.0 Hz], 126.4
3
1
[q, J (19F,13C) = 5.3 Hz], 123.5 [q, J (19F,13C) = 273.6 Hz], 87.8,
13C NMR (100 MHz, CDCl3): d = 156.2, 133.0, 132.11, 132.10 [q,
4J (19F,13C) = 1.3 Hz], 132.0 [q, 2J (19F,13C) = 32.8 Hz], 129.1,
128.4, 127.0, 125.7 [q, 3J (19F,13C) = 3.6 Hz], 123.7 [q, 1J
(19F,13C) = 272.4 Hz], 88.0, 41.4.
45.0 [q, 4J (19F,13C) = 2.7 Hz].
19F NMR (376 MHz, CDCl3): d = –62.9.
GC-MS (70 eV): m/z (%) = 323 (M+, 0.7), 215 (12), 214 (100), 194
(49), 186 (16), 166 (70), 152 (10), 146 (23), 145 (59), 135 (12), 125
(10), 116 (12), 110 (73), 109 (40), 95 (11), 91 (8), 77 (8), 75 (9), 69
(9), 65 (15), 51 (10), 45 (5).
19F NMR (376 MHz, CDCl3): d = –67.2.
Synthesis 2010, No. 18, 3195–3203 © Thieme Stuttgart · New York