3622
A. Kudelko / Tetrahedron 68 (2012) 3616e3625
C6eCH2), 3.32 (1H, dd, J 4.5 Hz and 14.1 Hz, C6eCH2), 3.67 (1H, m,
C6eH), 7.18e7.36 (5H, m, Ph), 9.32 (1H, s, NH); dC (CDCl3) 23.9, 37.0,
41.0, 127.2, 128.5, 129.3, 136.1, 144.5, 161.3; nmax (ATR) 3187, 3110,
3032, 2911, 2162, 1949, 1734, 1660, 1602, 1495, 1479, 1451, 1373,
1354, 1332, 1306, 1259, 1223, 1148, 1079, 1039, 1024, 944, 912, 808,
d, J 7.8 Hz, SH), 3.24 (1H, dd, J 7.8 Hz and 14.4 Hz, PheCH2), 3.45 (1H,
dd, J 7.8 Hz and 14.4 Hz, PheCH2), 4.40 (1H, q, J 7.8 Hz, C2eCH),
7.12e7.25 (5H, m, Ph), 7.32e7.44 (3H, m, C5ePh: H30, H40, H50), 7.93
(2H, d, J 7.8 Hz, C5ePh: H20, H60); dC (CDCl3) 35.3, 42.4, 47.5, 123.6,
127.0, 127.3, 128.3, 128.7, 129.0, 131.9, 136.8, 164.9, 167.3; nmax (ATR)
3063, 3028, 2915, 2569, 1714, 1608, 1559, 1541, 1490, 1449, 1372,
1273, 1228, 1175, 1157, 1092, 1070, 964, 946, 925, 843, 777, 748, 727,
776, 745, 733, 695 cmꢁ1
.
4.7.3. 2-1-Mercapto-2-phenylethyl-5-methyl-1,3,4-oxadiazole
(7b). Colourless oil (0.36 g, 15% yield); Rf (benzene/ethyl acetate,
1:3 v/v) 0.44; [Found: C, 59.88; H, 5.42; N, 12.65. C11H12N2OS re-
698, 685 cmꢁ1
.
4.7.8. 6-Phenyl-1,3,4-thiadiazin-5(6H)-one (6e). Colourless solid
(1.12 g, 53% yield); mp 166e168 ꢀC; Rf (benzene/ethyl acetate, 1:3 v/
v) 0.56; [Found: C, 56.18; H, 4.17; N, 14.50. C9H8N2OS requires C,
quires C, 59.97; H, 5.50; N, 12.71%]; lmax (MeOH): 207 nm (
3
ꢂ10ꢁ3
17.31 cmꢁ1Mꢁ1); dH (300 MHz, CDCl3, Me4Si) 2.24 (1H, d, J 7.8 Hz,
SH), 2.51 (1H, s, CH3), 3.24 (1H, dd, J 7.8 Hz and 14.1 Hz, PheCH2),
3.46 (1H, dd, J 7.8 Hz and 14.1 Hz, PheCH2), 4.38 (1H, q, J 7.8 Hz,
C2eCH), 7.17e7.29 (5H, m, Ph); dC (CDCl3) 10.9, 42.2, 47.5, 127.2,
128.6, 129.0, 136.8, 164.0, 167.5; nmax (ATR) 3028, 2927, 2569, 1671,
1588, 1561, 1494, 1454, 1437, 1390, 1347, 1222, 1078, 1030, 973, 954,
56.22; H, 4.20; N, 14.56%]; lmax (MeOH): 204 nm
(
3
ꢂ10ꢁ3
19.06 cmꢁ1Mꢁ1), 294 (2.25); dH (300 MHz, DMSO-d6, Me4Si) 4.99
(1H, s, C6eH), 7.24e7.40 (5H, m, Ph), 7.86 (1H, s, C2eH), 10.12 (1H, s,
NH); dC (DMSO-d6) 42.3, 127.6, 128.8, 129.1, 135.3, 153.8, 159.2; nmax
(ATR) 3194, 2962, 2163, 1959, 1652, 1581, 1494, 1454, 1366, 1259,
749, 732, 698, 666 cmꢁ1
.
1148, 1074, 1017, 928, 797, 730, 694 cmꢁ1
.
4.7.4. 6-Benzyl-2-ethyl-1,3,4-thiadiazin-5(6H)-one (6c). Colourless
solid (1.34 g, 52% yield); mp 65e67 ꢀC; Rf (benzene/ethyl acetate,
1:3 v/v) 0.66; [Found: C, 61.46; H, 5.99; N, 11.91. C12H14N2OS re-
4.7.9. 2-(1-Mercapto-1-phenylmethyl)-1,3,4-oxadiazole
(7e). Colourless oil (0.42 g, 20% yield); Rf (benzene/ethyl acetate,
1:3 v/v) 0.63; [Found: C, 56.14; H, 4.15; N, 14.48. C9H8N2OS requires
C, 56.22; H, 4.20; N, 14.56%]; dH (300 MHz, CDCl3, Me4Si) 2.04 (1H,
br s, SH), 5.21 (1H, br s, CH), 7.26e7.39 (5H, m, Ph), 8.42 (1H, s,
HeC5); dC (CDCl3) 50.1, 128.7, 128.9, 129.1, 133.6, 154.8, 167.5; lmax
quires C, 61.50; H, 6.03; N, 11.95%]; lmax (MeOH): 207 nm (
3
ꢂ10ꢁ3
17.19 cmꢁ1Mꢁ1), 286 (3.64); dH (300 MHz, CDCl3, Me4Si) 1.18 (3H, t, J
7.2 Hz, C2eCH2CH3), 2.45 (2H, q, J 7.2 Hz, C2eCH2CH3), 2.83 (1H, dd,
J 4.8 Hz and 14.1 Hz, C6eCH2), 3.30 (1H, dd, J 4.8 Hz and 14.1 Hz,
C6eCH2), 3.68 (1H, m, C6eH), 7.19e7.36 (5H, m, Ph), 9.37 (1H, s,
NH); dC (CDCl3) 11.5, 31.2, 37.1, 40.9, 127.2, 128.5, 129.3, 136.1, 149.6,
161.5; nmax (ATR) 3192, 3105, 3065, 2974, 2899, 2162, 1950, 1655,
1604,1495,1452,1377,1351,1332,1316,1259,1228,1179,1133,1079,
(MeOH): 204 nm (
3
ꢂ10ꢁ3 22.83 cmꢁ1Mꢁ1); nmax (ATR) 3138, 3119,
2954, 2569, 2162, 1978, 1563, 1510, 1495, 1455, 1326, 1302, 1231,
1092, 1077, 1028, 1003, 972, 958, 899, 849, 730, 712, 695 cmꢁ1
.
4.7.10. 2-Methyl-6-phenyl-1,3,4-thiadiazin-5(6H)-one
(6f). Colourless solid (1.09 g, 48% yield); mp 158e160 ꢀC; Rf (ben-
zene/ethyl acetate, 1:3 v/v) 0.58; [Found: C, 58.19; H, 4.83; N, 13.60.
C10H10N2OS requires C, 58.22; H, 4.89; N, 13.57%]; lmax (MeOH):
1063, 1038, 1024, 961, 916, 810, 770, 732, 695 cmꢁ1
.
4.7.5. 5-Ethyl-2-(1-mercapto-2-phenylethyl)-1,3,4-oxadiazole
(7c). Colourless oil (0.64 g, 25% yield); Rf (benzene/ethyl acetate,
1:3 v/v) 0.58; [Found: C, 61.43; H, 5.95; N, 11.89. C12H14N2OS re-
205 nm (
3
ꢂ10ꢁ3 17.15 cmꢁ1Mꢁ1), 288 (2.85); dH (300 MHz, CDCl3,
Me4Si) 2.20 (3H, s, C2eCH3), 4.64 (1H, s, C6eH), 7.29e7.38 (5H, m,
Ph), 9.40 (1H, s, NH); dC (CDCl3) 23.8, 42.9, 127.5, 128.6, 129.0, 135.4,
144.9, 160.0; nmax (ATR) 3193, 3070, 2943, 2161, 1980, 1655, 1598,
1498, 1459, 1430, 1378, 1367, 1330, 1301, 1249, 1177, 1157, 1126, 1080,
quires C, 61.50; H, 6.03; N, 11.95%]; lmax (MeOH): 206 nm (
3
ꢂ10ꢁ3
17.28 cmꢁ1Mꢁ1); dH (300 MHz, CDCl3, Me4Si) 1.24 (3H, t, J 7.2 Hz,
C5eCH2CH3), 2.14 (1H, d, J 7.2 Hz, SH), 2.75 (2H, q, J 7.2 Hz,
C5eCH2CH3), 3.17 (1H, dd, J 7.2 Hz and 13.8 Hz, PheCH2), 3.36 (1H,
dd, J 7.2 Hz, 13.8 Hz, PheCH2), 4.30 (1H, q, J 7.2 Hz, C2eCH),
7.10e7.25 (5H, m, Ph); dC (CDCl3) 10.6, 19.1, 42.3, 47.6, 127.3, 128.6,
129.1, 136.8, 164.7, 167.3; nmax (ATR) 3028, 2981, 2939, 2569, 1670,
1581, 1559, 1494, 1454, 1380, 1259, 1184, 1064, 1029, 981, 958, 799,
1029, 1004, 977, 928, 899, 866, 853, 801, 747, 699, 668 cmꢁ1
.
4.7.11. 2-(1-Mercapto-1-phenylmethyl)-5-methyl-1,3,4-oxadiazole
(7f). Colourless oil (0.79 g, 35% yield); Rf (benzene/ethyl acetate,1:3
v/v) 0.43; [Found: C, 58.16; H, 4.81; N, 13.51. C10H10N2OS requires C,
58.22; H, 4.89; N, 13.57%]; dH (300 MHz, DMSO-d6, Me4Si) 1.81 (3H,
s, C2eCH3), 2.49 (1H, d, J 7.2 Hz, SH), 5.61 (1H, d, J 7.2 Hz, CH),
7.21e7.41 (5H, m, Ph); dC (DMSO-d6) 10.3, 48.2, 127.1, 128.6, 129.0,
134.5, 163.8, 165.2; nmax (ATR) 2953, 2567, 2161, 1979, 1582, 1557,
1485,1454,1389,1351,1302,1225,1197,1184,1143,1076,1049,1029,
746, 698 cmꢁ1
.
4. 7. 6. 6-Benzyl-2-phenyl-1, 3, 4-thiadi azin-5(6H)-one
(6d). Colourless solid (0.74 g, 24% yield); mp 85e87 ꢀC; Rf (ben-
zene/ethyl acetate, 5:1 v/v) 0.46; [Found: C, 68.01; H, 4.96; N, 9.86.
C16H14N2OS requires C, 68.05; H, 5.00; N, 9.91%]; lmax (MeOH):
988, 975, 953, 850, 774, 751, 732, 697, 665 cmꢁ1
.
204 nm (
3
ꢂ10ꢁ3 31.35 cmꢁ1Mꢁ1), 251 (14.16), 275 (11.56), 312
(8.38); dH (600 MHz, CDCl3, Me4Si) 2.84 (1H, dd, J 5.4 Hz and
13.8 Hz, C6eCH2), 3.36 (1H, dd, J 5.4 Hz and 13.8 Hz, C6eCH2), 3.77
(1H, dd, J 5.4 Hz and 13.8 Hz, C6eH), 7.21 (2H, d, J 8.4 Hz, C6ePh:
H200, H600), 7.28e7.35 (3H, m, C6ePh: H300, H400, H500), 7.39e7.44
(3H, m, C2ePh: H30, H40, H50), 7.21 (2H, d, J 8.4 Hz, C6ePh: H200,
H600), 7.81 (2H, d, J 7.8 Hz, C2ePh: H20, H60), 9.63 (1H, s, NH); dC
(CDCl3) 36.4, 41.4, 127.3, 127.4,128.3, 128.6, 128.7,129.5, 130.9, 134.7,
136.1, 145.5, 162.2; nmax (ATR) 3193, 3096, 2922, 2164, 1948, 1647,
1585, 1568, 1492, 1481, 1454, 1446, 1359, 1336, 1312, 1260, 1149,
4.7.12. 2-Ethyl-6-phenyl-1,3,4-thiadiazin-5(6H)-one
(6g). Yellow
solid (1.11 g, 46% yield); mp 101e103 ꢀC; Rf (benzene/ethyl acetate,
1:3 v/v) 0.60; [Found: C, 59.90; H, 5.45; N, 12.69. C11H12N2OS re-
quires C, 59.97; H, 5.50; N, 12.71%]; lmax (MeOH): 205 nm (
3
ꢂ10ꢁ3
17.03 cmꢁ1Mꢁ1), 290 (3.39); dH (300 MHz, CDCl3, Me4Si) 1.25 (3H, t,
J 7.5 Hz, C2eCH2CH3), 2.60 (2H, q, J 7.5 Hz, C2eCH2CH3), 4.76 (1H, s,
C6eH), 7.38e7.42 (5H, m, Ph), 9.65 (1H, s, NH); dC (CDCl3) 11.6, 31.3,
43.0, 127.8, 128.8, 129.2, 135.8, 150.4, 160.7; nmax (ATR) 3201, 3068,
2937, 2161, 1980, 1655, 1599, 1497, 1455, 1420, 1369, 1329, 1249,
1168, 1112, 1077, 1023, 1002, 956, 929, 903, 863, 810, 778, 744,
1117, 1075, 1039, 1001, 961, 923, 809, 761, 745, 690 cmꢁ1
.
695 cmꢁ1
.
4.7.7. 2-(1-Mercapto-2-phenylethyl)-5-phenyl-1,3,4-oxadiazole
(7d). Colourless oil (1.80 g, 58% yield); Rf (benzene/ethyl acetate,
5:1 v/v) 0.59; [Found: C, 67.92; H, 4.95; N, 9.84. C16H14N2OS re-
4.7.13. 5-Ethyl-2-(1-mercapto-1-phenylmethyl)-1,3,4-oxadiazole
(7g). Colourless oil (0.97 g, 40% yield); Rf (benzene/ethyl acetate,
1:3 v/v) 0.53; [Found: C, 60.04; H, 5.45; N, 12.64. C11H12N2OS re-
quires C, 68.05; H, 5.00; N, 9.91%]; lmax (MeOH): 205 nm (
3
ꢂ10ꢁ3
41.69 cmꢁ1Mꢁ1), 254 (29.72); dH (600 MHz, CDCl3, Me4Si) 2.24 (1H,
quires C, 59.97; H, 5.50; N, 12.71%]; lmax (MeOH): 204 nm (
3
ꢂ10ꢁ3