反应详情

A mixture of 13.6 g. (0.5 M) of 7-aminocephalosporanic acid (7-ACA) in 100 ml. of water and 50 ml. of acetone are brought to pH 8 with sodium hydroxide while stirring. 9.8 g. (0.57 M) of 2-methyl-1,3,4-thiadiazole-5-thiol are added and the mixture is heated at 80° for 4 hours. After cooling to 5°, this is acidified to pH 3.5 with dilute hydrochloric acid and stirred for 15 minutes. The precipitated solid is filtered under suction and washed with acetone. This 3-[[(5-methyl-1,3,4-thiadiazol-2-yl)thio]-methyl]-7-amino-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid is purified by dissolving in sodium bicarbonate solution and reprecipitating with 2N hydrochloric acid; yield 12.7 g., m.p. 206°.

1. additionA mixture of 13.6 g
2. temperaturethe mixture is heated at 80° for 4 hours
3. temperatureAfter cooling to 5°
4. stirringstirred for 15 minutes
5. filtrationThe precipitated solid is filtered under suction
6. washwashed with acetone
7. customThis 3-[[(5-methyl-1,3,4-thiadiazol-2-yl)thio]-methyl]-7-amino-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid is purified
8. dissolutionby dissolving in sodium bicarbonate solution
9. customreprecipitating with 2N hydrochloric acid