反应详情

A 500 ml reactor equipped with mechanical stirrer, thermometer and condenser was loaded with 200 ml of water, 30 g of 2-acetylamino-4,5,6,7-tetrahydro-benzothiazole-6-carboxylic acid ethyl ester [(II), R1=ethyl, R=—NH—CO—CH3] and 52.2 g of 30% sodium hydroxide, keeping the temperature below 30° C.; during the addition the solid gradually solubilized until complete dissolution. After 2 hours, glacial acetic acid was dropwise added to pH=4.5-5.5; after approx. 1 hour the precipitated white solid was filtered, washed with 70 ml of water and dried to obtain 24.8 g of 2-acetylamino-4,5,6,7-tetrahydro-benzothiazole-6-carboxylic acid.

1. customA 500 ml reactor equipped with mechanical stirrer
2. customthe temperature below 30° C.
3. additionduring the addition the solid
4. dissolutiongradually solubilized until complete dissolution
5. filtrationafter approx. 1 hour the precipitated white solid was filtered
6. washwashed with 70 ml of water
7. customdried