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S. S. REDDY AND G. L. D. KRUPADANAM
LSIMS: m=z 354 [M þ H]þ. Anal. calcd. for C16H16ClNO4S: C, 54.31; H, 4.56; N,
3.96. Found C, 54.19; H, 4.62; N, 4.05%.
Ethyl-[2-(6-bromo-2H-chromene-3yl)-4-oxo-1,3-thiazolidin-3-yl]acetate
(6c). Yield 71%; IR (KBr): 1678 cmꢀ1 (C¼O) (thiazolidinone C¼O) and 1741 cmꢀ1
(ester C¼O); UV (MeOH): 338 nm (log e 4.1), 281 nm (log e 4.5), and 246 nm (log e
1
4.1); H NMR (CDCl3): d 7.21 (m, H-70), 7.11 (d, J ¼ 3.0 Hz, H-50), 6.70 (d,
J ¼ 8.3 Hz, H-80), 6.42 (s, H-40), 5.46 (s, H-2), 4.85 (d, J ¼ 13.5 Hz, OCH of
20-OCH2), 4.59 (d, J ¼ 13.5 Hz, OCH of 20-OCH2), 4.38 (d, J ¼ 17.3 Hz, S-CH),
4.18 (q, J ¼ 6.7 Hz, COOCH2CH3), 3.66 (q, J ¼ 6.7 Hz, N-CH2), 3.55 (d, J ¼ 17.3 Hz,
S-CH), 1.26 (t, J ¼ 6.7 Hz, COOCH2CH3); 13C NMR (CDCl3): d 172.3 (C¼O at
C-4), 168.2 (COOCH2CH3), 154.8 (C-8a), 132.3 (C-30), 130.7 (C-70), 129.8 (C-50),
129.3 (C-40), 124.2 (C-40a), 112.6 (C-80), 109.8 (C-60), 64.8 (C-20-OCH2), 62.1
(C-2), 61.6 (COOCH2CH3), 41.5 (N-CH2), 31.4 (S-CH2), 14.0 (COOCH2CH3);
LSIMS: m=z 399 [M þ H]þ. Anal. calcd. for C16H16BrNO4S: C, 48.25; H, 4.05; N,
3.52. Found C, 48.42; H, 3.94; N, 3.38%.
Ethyl-[2-(6-methoxy-2H-chromene-3yl)-4-oxo-1,3-thiazolidin-3-yl]acetate
(6d). Yield 68%; IR (KBr): 1690 cmꢀ1 (C¼O) (thiazolidinone C¼O) and 1736 cmꢀ1
(ester C¼O); UV (MeOH): 351 nm (log e 4.4), 276 nm (log e 4.3), and 233 nm (log e
1
4.1); H NMR (CDCl3): d 6.79–7.16 (m, H-50,70,80), 6.48 (s, H-40), 5.37 (s, H-2),
4.80 (d, J ¼ 13.5 Hz, OCH of 20-OCH2), 4.54 (d, J ¼ 13.5 Hz, OCH of 20-OCH2),
4.38 (d, J ¼ 17.3 Hz, S-CH), 4.10 (q, J ¼ 6.7 Hz, COOCH2CH3), 3.77 (s, 60-OCH3),
3.52 (m, S-CH and N-CH2), 1.26 (t, J ¼ 6.7 Hz, COOCH2CH3); 13C NMR (CDCl3):
d 172.5 (C¼O at C-4), 168.4 (COOCH2CH3), 153.8 (C-60), 150.1 (C-8a), 130.1 (C-30),
126.3 (C-40), 122.8 (C-40a), 117.0 (C-70), 114.6 (C-50), 112.2 (C-80), 64.6 (C-20-OCH2),
62.5 (C-2), 61.9 (COOCH2CH3), 55.4 (C-60-OCH3), 41.8 (N-CH2), 31.6 (S-CH2),
14.3 (COOCH2CH3); LSIMS: m=z 350 [M þ H]þ. Anal. calcd. for C17H19NO5S:
C, 58.44; H, 5.48; N, 4.01. Found C, 58.60; H, 5.29; N, 4.12%.
Ethyl-[2-(8-ethoxy-2H-chromene-3yl)-4-oxo-1,3-thiazolidin-3-yl]acetate
(6e). Yield 74%; IR (KBr): 1682 cmꢀ1 (C¼O) (thiazolidinone C¼O) and 1738 cmꢀ1
(ester C¼O); UV (MeOH): 344 nm (log e 4.7), 267 nm (log e 4.2), and 236 nm (log e
1
4.1); H NMR (CDCl3): d 6.59–6.94 (m, H-50,60,70), 6.55 (s, H-40), 5.57 (s, H-2),
4.86 (d, J ¼ 13.5 Hz, OCH of 20-OCH2), 4.65 (d, J ¼ 13.5 Hz, OCH of 20-OCH2),
4.47 (d, J ¼ 17.3 Hz, S-CH), 4.25 (q, J ¼ 6.7 Hz, COOCH2CH3), 4.12 (q, J ¼ 6.7 Hz,
80-OCH2CH3), 3.73 (m, S-CH and N-CH2), 1.51 (t, J ¼ 6.7 Hz, 80-OCH2CH3), 1.32
(t, J ¼ 6.7 Hz, COOCH2CH3); 13C NMR (CDCl3): d 172.3 (C¼O at C-4), 167.9
(COOCH2CH3), 147.2 (C-80a), 145.6 (C-80), 124.8 (C-30), 122.3 (C-40a), 121.4
(C-40), 120.5 (C-50), 119.8 (C-70), 119.3 (C-60), 64.8 (C-20-OCH2), 64.1 (80-O-
CH2CH3), 62.9 (C-2), 61.7 (COOCH2CH3), 41.3 (N-CH2), 31.2 (S-CH2), 14.5
(80-OCH2CH3), 13.8 (COOCH2CH3); LSIMS: m=z 364 [M þ H]þ. Anal. calcd. for
C18H21NO5S: C, 59.49; H, 5.82; N, 3.85. Found C, 59.63; H, 5.61; N, 3.94%.
ACKNOWLEDGMENTS
One of the authors (S. S. R.) thanks the Council of Scientific and Industrial
Research, New Delhi, for financial support and grants of junior and senior research