and ethyl acetate (9:1) gave unreacted benzyl chloride. Elution
next with the same solvent mixture (4:1) gave 5q (584 mg, 81%)
(liquid) (Found: C, 70.21; H, 6.41; N, 14.85. C11H12N2O
requires C, 70.19; H, 6.43; N, 14.88%); νmax(neat)/cmϪ1 3296,
1619, 1539, 1443, 1386, 1350, 1027, 889, 771, 732, 691; δH(80
MHz; CDCl3) 2.17 (3H, s, CH3), 4.30 (2H, s, br, CH2), 5.42
(1H, s, C4-H), 7.09–7.42 (6H, m, ArH, NH).
H, 5.17; N, 17.88; S, 20.50. C6H8N2OS requires C, 46.14; H,
5.16; N, 17.93; S, 20.52%); νmax(neat)/cmϪ1 2960, 1689, 1398,
1194, 1075, 1008, 928, 828, 774; δH(80 MHz; CDCl3) 1.20 (3H,
t, J 8, CH3CH2), 2.80 (3H, s, CH3), 3.20 (2H, q, J 8, CH3CH2).
3-(n-Butanoyl)-4-methyl-1,2,5-thiadiazole 6c. (Found: C,
49.41; H, 5.90; N, 16.44; S, 18.88. C7H10N2OS requires C, 49.39;
H, 5.92; N, 16.46; S, 18.83%); νmax(neat)/cmϪ1 2960, 1697, 1452,
1398, 1190, 966; δH(80 MHz; CDCl3) 0.97 (3H, t, J 8, CH3CH2),
1.72 (2H, quintet, J 8, CH3CH2CH2), 2.78 (3H, s, CH3), 3.13
(2H, t, J 8, CH3CH2CH2).
4-Ethyl-3-methyl-5-phenylisoxazole 5t
Compound 5t was prepared according to the literature pro-
cedure5 (liquid) (Found: C, 76.95; H, 6.98; N, 7.51. C12H13NO
requires C, 76.98; H, 7.00; N, 7.48%); νmax(neat)/cmϪ1 2960,
1619, 1436, 1414, 1059, 1011, 953, 908, 768, 713, 691; δH(80
MHz; CDCl3) 1.18 (3H, t, J 8, CH3CH2), 2.27 (3H, s, CH3), 2.59
(2H, q, J 8, CH3CH2), 7.30–7.79 (5H, m, ArH).
3-Methyl-4-(3-phenylpropanoyl)-1,2,5-thiadiazole 6e. (Found:
C, 62.10; H, 5.19; N, 12.03; S, 13.83. C12H12N2OS requires C,
62.05; H, 5.21; N, 12.06; S, 13.80%); νmax(neat)/cmϪ1 3008, 2912,
1686, 1484, 1398, 1027, 950, 828, 694; δH(80 MHz; CDCl3) 2.77
(3H, s, CH3), 3.05 (2H, t, J 8, PhCH2), 3.48 (2H, t, J 8,
CH2CH2), 7.23 (5H, s, ArH).
4-Bromo-3,5-bis(4-methylphenyl)isoxazole 5y
3-Benzoyl-4-isopropyl-1,2,5-thiadiazole 6f. (Found: C, 62.08;
H, 5.20; N, 12.08; S, 13.84. C12H12N2OS requires C, 62.05; H,
5.21; N, 12.06; S, 13.80%); νmax(neat)/cmϪ1 2976, 1657, 1590,
1446, 1392, 1337, 1286, 1219, 1078, 912, 694; δH(80 MHz;
CDCl3) 1.34 (6H, d, J 8, 2CH3), 3.73 [1H, septet, J 8,
CH(CH3)2], 7.38–7.68 (3H, m, ArH), 7.92–8.18 (2H, m, ArH).
3-(4-Methylbenzoyl)-4-phenyl-1,2,5-thiadiazole 6h. (Found:
C, 68.50; H, 4.33; N, 10.01; S, 11.40. C16H12N2OS requires C,
68.55; H, 4.31; N, 9.99; S, 11.44%); νmax(KBr)/cmϪ1 1667, 1590,
1446, 1385, 1273, 1248, 1158, 1078, 1011, 896, 822, 688; δH(80
MHz; CDCl3) 2.30 (3H, s, CH3), 7.00–8.08 (9H, m, ArH).
3-(4-Fluorobenzoyl)-4-phenyl-1,2,5-thiadiazole 6i. (Found: C,
63.35; H, 3.18; N, 9.88; S, 11.30. C15H9FN2OS requires C,
63.37; H, 3.19; N, 9.85, S, 11.28%); νmax(KBr)/cmϪ1 1657, 1584,
1494, 1456, 1408, 1273, 1232, 1152, 896, 755, 694; δH(80 MHz;
CDCl3) 7.09–8.14 (9H, m, ArH).
3-(4-Methoxybenzoyl)-4-(4-methoxyphenyl)-1,2,5-thiadiazole
6k. (Found: C, 62.55; H, 4.30; N, 8.55; S, 9.85. C17H14N2O3S
requires C, 62.56; H, 4.32; N, 8.58; S, 9.82%); νmax(neat)/cmϪ1
1651, 1593, 1449, 1414, 1385, 1302, 1254, 1152, 896; δH(80
MHz; CDCl3) 3.77 (3H, s, OCH3 at C3), 3.84 (3H, s, OCH3 at
C4), 6.69–7.18 (4H, m, ArH), 7.52–8.17 (4H, m, ArH).
3-(4-Chlorobenzoyl)-4-(4-chlorophenyl)-1,2,5-thiadiazole 6m.
(Found: C, 53.71; H, 2.42; N, 8.33; S, 9.52. C15H8Cl2N2OS
requires C, 53.75; H, 2.41; N, 8.36; S, 9.56%); νmax(KBr)/cmϪ1
1657, 1577, 1478, 1430, 1395, 1369, 1273, 1155, 1088, 1008, 892,
768; δH(80 MHz; CDCl3) 7.20–8.00 (8H, m, ArH).
Compound 5y was prepared according to the literature proce-
dure:8j mp 175–177 ЊC (CCl4) (Found: C, 62.14; H, 4.32; N,
4.30. C17H14BrNO requires C, 62.19; H, 4.30; N, 4.27%);
νmax(KBr)/cmϪ1 1603, 1580, 1555, 1491, 1411, 1369, 1177, 1100,
988, 924, 816, 720; δH(80 MHz; CDCl3) 2.42 (6H, s, 2CH3), 7.30
(4H, d, J 7, ArH), 7.76 (2H, d, J 7, ArH), 7.98 (2H, d, J 7,
ArH).
4-Bromo-3,5-bis(4-methoxyphenyl)isoxazole 5z
Compound 5z was prepared according to the literature proce-
dure:8j mp 146–147 ЊC (CCl4) (Found: C, 56.70; H, 3.91; N,
3.88. C17H14BrNO3 requires C, 56.67; H, 3.92; N, 3.89%);
νmax(KBr)/cmϪ1 1600, 1491, 1417, 1372, 1292, 1251, 1177, 1100,
1020, 928, 828, 729; δH(80 MHz; CDCl3) 3.84 (6H, s, 2CH3O),
7.00 (4H, d, J 7, ArH), 7.82 (2H, d, J 7, ArH), 8.04 (2H, d, J 7,
ArH).
4-Bromo-3,5-bis(4-chlorophenyl)isoxazole 5zЈ
Compound 5zЈ was prepared according to the literature proce-
dure:8j mp 124–126 ЊC (CCl4) (Found: C, 48.77; H, 2.19; N,
3.81. C15H8BrCl2NO requires C, 48.81; H, 2.18; N, 3.79%);
νmax(KBr)/cmϪ1 1596, 1475, 1404, 1088, 1011, 931, 822, 723;
δH(80 MHz; CDCl3) 7.50 (4H, d, J 8, ArH), 7.81 (2H, d, J 8,
ArH), 8.03 (2H, d, J 8, ArH).
General procedure for the synthesis of 4-substituted 3-acyl- and
3-aroyl-1,2,5-thiadiazoles 6 and 3-(1-acetyl-1-chloro- and 3-(1-
benzoyl-1-chloro-alkyl)-1,2,5-thiadiazoles 8
3-Acetamido-4-acetyl-1,2,5-thiadiazole 6n. (Found: C, 38.88;
H, 3.80; N, 22.70; S, 17.35. C6H7N3O2S requires C, 38.91; H,
3.81; N, 22.69; S, 17.31%); νmax(KBr)/cmϪ1 3296, 1699, 1670,
1523, 1488, 1417, 1369, 1235, 1081, 1014, 960, 876, 841, 688;
To a solution of 5 (1.00–2.76 mmol) in toluene (30 ml) was
added 1 (1.00–3.00 mmol), which was heated for the appropri-
ate time. The color of the solution immediately turned dark.
The reaction mixture was cooled to room temperature when a
spot corresponding to 5 (Rf = 0.47, n-hexane–CH3CO2Et = 4:1)
had disappeared on TLC. The reaction mixture was filtered to
remove the toluene-insoluble solids. After removal of toluene in
vacuo, the residue was chromatographed on a silica gel column
(2.5 × 5 cm). Elution with n-hexane gave a trace amount of
sulfur. Elution next with a mixture of n-hexane and benzene
(3:1) gave unreacted S4N4 (less than 10 mg). Elution with the
same solvent mixture (1:1) gave 6. When compound 5 had a
substituent (R2 = Me, Et) at C4, elution with a mixture of
CCl4 and CHCl3 (2:1) gave 8. When R2 was Br (5x), elution
with a mixture of CCl4 and CHCl3 (2:1) gave the starting com-
pound 5x (30%). Elution with the same solvent mixture gave 6d
(41%). Consult Table 1 and Table 2 for the melting points of 6
and the reaction conditions and yields to form 6 and 8,
respectively.
δ (80 MHz; CDCl ) 2.36 [3H, s, CH C(᎐O)NH], 2.75 [3H, s,
᎐
H
3
3
CH C(᎐O)], 10.43 (1H, s, NH).
᎐
3
3-Acetyl-4-benzamido-1,2,5-thiadiazole 6o. (Found: C, 53.40;
H, 3.66; N, 16.95; S, 12.99. C11H9N3O2S requires C, 53.43; H,
3.67; N, 16.99; S, 12.97%); νmax(KBr)/cmϪ1 3296, 1692, 1664,
1529, 1491, 1379, 1321, 1248, 1104, 1056, 1020, 969, 832, 796,
704; δH(80 MHz; CDCl3) 2.80 (3H, s, CH3), 7.38–7.75 (3H, m,
ArH), 7.86–8.19 (2H, m, ArH), 11.40 (1H, s, NH).
3-Acetyl-4-trifluoroacetamido-1,2,5-thiadiazole 6p. (Found:
C, 30.15; H, 1.67; N, 17.55; S, 13.44. C6H4F3N3O2S requires C,
30.13; H, 1.69; N, 17.57; S, 13.40%); νmax(KBr)/cmϪ1 3264, 1744,
1670, 1542, 1494, 1296, 1136; δH(80 MHz; CDCl3) 2.78 (3H, s,
CH3), 11.40 (1H, s, NH).
3-Acetyl-4-benzylamino-1,2,5-thiadiazole 6q. (Found: C,
56.60; H, 4.77; N, 18.05; S, 13.70. C11H11N3OS requires C,
56.63; H, 4.75; N, 18.01; S, 13.74%); νmax(neat)/cmϪ1 3376, 1664,
1542, 1484, 1372, 1017, 944, 729, 697, 624; δH(80 MHz; CDCl3)
2.66 (3H, s, CH3), 4.64 (2H, d, J 7, ArCH2), 7.19–7.66 (6H, m,
ArH, NH).
3-(1-Acetyl-1-chloroethyl)-1,2,5-thiadiazole 8a. (Found: C,
37.77; H, 3.68; N, 14.66; S, 16.85. C6H7ClN2OS requires C,
37.80; H, 3.70; N, 14.69; S, 16.82%); νmax(neat)/cmϪ1 1718, 1433,
1347, 1196, 1107, 1091, 1056, 960, 886, 838, 793, 742; δH(80
3-Acetyl-4-methyl-1,2,5-thiadiazole 6a. (Found: C, 42.21; H,
4.26; N, 19.66; S, 22.58. C5H6N2OS requires C, 42.24; H, 4.25;
N, 19.70; S, 22.55%); νmax(neat)/cmϪ1 1689, 1398, 1232, 1065,
947, 848, 828, 768, 617; δH(80 MHz; CDCl3) 2.17 [3H, s,
CH C(᎐O)], 2.81 (3H, s, CH ).
᎐
3
3
3-Methyl-4-propanoyl-1,2,5-thiadiazole 6b. (Found: C, 46.11;
J. Chem. Soc., Perkin Trans. 1, 1998
2179