850
H Nagarajaiah et al.
2.4e 3-Ethoxycarbonylmethyl-5-(4-hydroxy-phenyl)- 32.81, 55.46, 56.73, 59.06, 60.64, 99.87, 104.89,
7-methyl-5H-thiazolo[3,2-a]pyrimidine-6-carboxylic 110.17, 115.65, 118.60, 131.97, 134.19, 146.64,
acid ethyl ester (5e): IR (KBr νmax, cm−1): 3344(OH), 147.28, 154.29, 165.39, 165.65, 168.1. CHNS found
3021, 2981 (CH), 1728, 1662 (C=O), 1472 (C=N). 1H (calc)%: C 58.32 (58.49), H 5.59 (5.73), N 6.48 (6.37),
NMR (400 MHz, DMSO): δ 1.16 (t, J = 7.2 Hz, 3H, S 7.41 (7.28).
-CH2CH3), 1.21 (t, J = 7.2 Hz, 3H,-CH2CH3), 2.23 (s,
3H, CH3), 3.29 (s, 2H, CH2), 4.00 (q, J = 7.2 Hz, 2H,
2.4i 3-Ethoxycarbonylmethyl-5-(3-methoxy-phenyl)-
CH2CH3), 4.10 (q, J = 7.2 Hz, 2H, CH2CH3), 5.96 (s,
7-methyl-5H-thiazolo[3,2-a]pyrimidine-6-carboxylic acid
1H, CH), 6.07 (s, 1H, S-CH), 6.66–7.05 (m, 4H, ArH),
methyl ester (5i): IR (KBr νmax, cm−1): 3021, 2981
9.50 (s, 1H, -OH). 13C NMR (DMSO) δ: 13.89, 14.12,
1
(CH), 1728, 1662 (C=O), 1472 (C=N). H NMR
23.18, 32.77, 56.53, 59.04, 61.07, 110.02, 104.93,
(400 MHz, DMSO): δ 1.21 (t, J = 7.2 Hz, 3H,
115.34, 127.32, 127.61, 131.86, 133.71, 154.16,
-CH2CH3), 2.38 (s, 3H, CH3), 3.29 (s, 2H, CH2), 3.76
157.36, 165.32, 165.59, 168.05. CHNS found (calc)%:
(s, 3H, -OCH3), 3.92 (s, 3H, -OCH3), 4.18 (q, J =
C 59.69 (59.81), H 5.51 (5.62), N 6.96 (6.87), S 7.97
7.2 Hz, 2H, CH2CH3), 6.16 (s, 1H, CH), 6.28 (s, 1H,
(8.11).
SH), 6.79–7.28 (m, 4H, ArH). 13C NMR (DMSO) δ:
13.96, 23.07, 32.08, 55.00, 56.71, 57.09, 61.32,102.13,
105.17, 112.35, 113.25, 118.21, 129.96, 130.25,
143.70, 154.05, 159.33, 160.46, 162.63, 165.36. CHNS
found (calc)%: C 59.69 (59.88), H 5.51 (5.53), N 6.96
(7.04), S 7.97 (7.71).
2.4f 3-Ethoxycarbonylmethyl-7-methyl-5-naphthalen-
1-yl-5H-thiazolo[3,2-a]pyrimidine-6-carboxylic acid
ethyl ester (5f): IR (KBr νmax, cm−1): 3056, 2990
1
(CH), 1725, 1667 (C=O), 1481 (C=N). H NMR
(300 MHz, CDCl3): δ 1.14 (t, J = 7.2 Hz, 3H,
-CH2CH3), 1.27 (t, J = 7.2 Hz, 3H,-CH2CH3), 2.51 (s,
3H, CH3), 3.28 (s, 2H, CH2), 4.06 (q, J = 7.2 Hz, 2H,
CH2CH3), 4.26 (q, J = 7.2 Hz, 2H, CH2CH3), 6.81 (S,
1H, CH), 7.05 (s, 1H, S-CH), 7.47–8.32 (m, 7H, ArH).
CHNS found (calc)%: C 66.03 (66.21), H 5.54 (5.66),
N 6.42 (6.29), S 7.35 (7.54).
2.4j 3-Ethoxycarbonylmethyl-5-(4-hydroxy-phenyl)-7-
methyl-5H-thiazolo[3,2-a]pyrimidine-6-carboxylic acid
methyl ester (5j): IR (KBr νmax, cm−1): 3348(OH),
3056, 2987 (CH), 1732, 1659 (C=O), 1486 (C=N). 1H
NMR (400 MHz, DMSO): δ 1.19 (t, J = 7.2 Hz, 3H,
CH2CH3), 2.46 (s, 3H, CH3), 3.29 (s, 2H, CH2), 3.84(s,
3H, OCH3), 4.22 (q, J = 7.2 Hz, 2H, CH2CH3), 6.10 (s,
1H, CH), 6.20 (s, 1H, SCH), 6.76–7.19 (m, 4H, ArH),
8.65 (s, 1H, -OH). CHNS found (calc)%: C 58.75
(58.71), H 5.19 (5.33), N 7.21 (7.10), S 8.26 (8.42).
2.4g 3-Ethoxycarbonylmethyl-7-methyl-5-thiophen-
2-yl-5H-thiazolo[3,2-a]pyrimidine-6-carboxylic acid
ethyl ester (5g): IR (KBr νmax, cm−1): 3082, 2982
1
(CH), 1725, 1655 (C=O), 1488 (C=N). H NMR
(300 MHz, CDCl3): δ 1.29 (t, J = 7.2 Hz, 3H,
-CH2CH3), 1.33 (t, J = 7.2 Hz, 3H,-CH2CH3), 2.58 (s,
3H, CH3), 3.28 (s, 2H, CH2), 4.20 (q, J = 7.2 Hz, 2H,
CH2CH3), 4.29 (q, J = 7.2 Hz, 2H, CH2CH3), 6.38 (s,
1H, CH), 6.50 (s, 1H, S-CH), 6.91–7.24 (m, 3H, ArH).
CHNS found (calc)%: C 55.08 (55.14), H 5.14 (5.17),
N 7.14 (6.97), S 16.34 (16.47).
2.4k 3-Ethoxycarbonylmethyl-7-methyl-5-naphthalen-
1-yl-5H-thiazolo[3,2-a]pyrimidine-6-carboxylic acid
methyl ester (5k): IR (KBr νmax, cm−1): 3031, 2998
1
(CH), 1727, 1653 (C=O), 1483 (C=N). H NMR
(300 MHz, CDCl3): δ 1.17 (t, J = 7.2 Hz, 3H,
-CH2CH3), 2.50 (s, 3H, CH3), 3.31 (s, 2H, CH2),
3.83(s, 3H, OCH3), 4.20 (q, J = 7.2 Hz, 2H, CH2CH3),
6.80 (s, 1H, CH), 6.85 (s, 1H, SCH), 7.37–8.42 (m, 7H,
ArH). CHNS found (calc)%: C 65.38 (65.27), H 5.25
(5.15), N 6.63 (6.71), S 7.59 (7.74).
2.4h 3-Ethoxycarbonylmethyl-5-(4-hydroxy-3-methoxy-
phenyl)-7-methyl-5H-thiazolo[3,2-a]pyrimidine-6-
carboxylic acid ethyl ester (5h): IR (KBr νmax, cm−1):
3387(OH), 3066, 2976 (CH), 1730, 1653 (C=O), 2.4l 3-Ethoxycarbonylmethyl-7-methyl-5-thiophen-2-
1
1484 (C=N). H NMR (400 MHz, DMSO): 1.18 (t, yl-5H-thiazolo[3,2-a]pyrimidine-6-carboxylic acid methyl
J = 7.2 Hz, 3H,-CH2CH3), 1.23 (t, J = 7.2 Hz, 3H,- ester (5l): IR (KBr νmax, cm−1): 3044, 2995 (CH),
CH2CH3), 2.47 (s, 3H, CH3), 3.38 (s, 2H, CH2), 3.83 1735, 1654 (C=O), 1489 (C=N). 1H NMR (300 MHz,
(s, 3H, -OCH3), 4.19 (q, J = 7.2 Hz, 2H, CH2CH3), CDCl3): δ 1.31 (t, J = 7.2 Hz, 3H,-CH2CH3), 2.57 (s,
4.25 (q, J = 7.2 Hz, 2H, CH2CH3), 5.85 (s, 1H, CH), 3H, CH3), 3.31 (s, 2H, CH2), 3.78 (s, 3H, -OCH3), 4.31
6.10 (s, 1H, S-CH), 6.74–6.85 (m, 3H, ArH), 7.77 (s, (q, J = 7.2 Hz, 2H, CH2CH3), 6.38 (s, 1H, CH), 6.50
1H, OH). 13C NMR (DMSO) δ: 13.87, 14.18, 23.17, (s, 1H, SCH), 6.88–7.25 (m, 3H, ArH). CHNS found