Table 1.
Inhibitory effect (mean ± standard error) of thiazolo[3,2-a]pyrimidine carboxylate derivatives at 500 mg/L on germination, shoot length and root length of Eleusine indica after 7 days. of treatment
| ||||
|---|---|---|---|---|
| Compound | R | Average percentage of control (%) | ||
| Germination | Shoot length | Root length | ||
| a | H | 10 ± 0 | 70 ± 9.0 | 13 ± 3.1 |
| b | 4-F | 0 ± 0 | 78 ± 3.9 | 0 ± 0 |
| c | 3-F | 0 ± 0 | 0 ± 0 | 0 ± 0 |
| d | 2-F | 53 ± 15.0 | 92 ± 7.5 | 14 ± 1.4 |
| e | 4-Cl | 0 ± 0 | 64 ± 4.8 | 0 ± 0 |
| f | 3-Cl | 0 ± 0 | 50 ± 10.3 | 0 ± 0 |
| g | 2-Cl | 0 ± 0 | 104 ± 7.3 | 0 ± 0 |
| h | 4-Br | 20 ± 0 | 64 ± 6.9 | 11 ± 0 |
| i | 3-Br | 10 ± 0 | 81 ± 0 | 11 ± 0 |
| j | 2-Br | 0 ± 0 | 72 ± 17.7 | 0 ± 0 |
| diuron | 0 ± 0 | 0 ± 0 | 0 ± 0 | |
a: 7-Methyl-5-phenyl-5H-thiazolo[3,2-a]pyrimidine-6-carboxylic acid ethyl ester; b: 5-(4-Fluoro-phenyl)-7-methyl-5H-thiazolo[3,2-a]pyrimidine-6-carboxylic acid ethyl ester; c: 5-(3-Fluoro-phenyl)-7-methyl-5H-thiazolo[3,2-a]pyrimidine-6-carboxylic acid ethyl ester; d: 5-(2-Fluoro-phenyl)-7-methyl-5H-thiazolo[3,2-a]pyrimidine-6-carboxylic acid ethyl ester; e: 5-(4-Chloro-phenyl)-7-methyl-5H-thiazolo[3,2-a]pyrimidine-6-carboxylic acid ethyl ester; f: 5-(3-Chloro-phenyl)-7-methyl-5H-thiazolo[3,2-a]pyrimidine-6-carboxylic acid ethyl ester; g: 5-(2-Chloro-phenyl)-7-methyl-5H-thiazolo[3,2-a]pyrimidine-6-carboxylic acid ethyl ester; h: 5-(4-Bromo-phenyl)-7-methyl-5H-thiazolo[3,2-a]pyrimidine-6-carboxylic acid ethyl ester; i: 5-(3-Bromo-phenyl)-7-methyl-5H-thiazolo[3,2-a]pyrimidine-6-carboxylic acid ethyl ester; j: 5-(2-Bromo-phenyl)-7-methyl-5H-thiazolo[3,2-a]pyrimidine-6-carboxylic acid ethyl ester.