反应详情

A suspension of 2-guanidino-4,5,6,7-tetrahydro-benzothiazole-4-carboxylic acid ethyl ester (5 mmol) and sodium hydroxide (20 mmol) in methanol/water (4:1, 10 ml) is stirred overnight at room temperature. The pH is set at 5 by adding 25% hydrochloric acid and the precipitated product is filtered off. In this way the title compound is obtained (671 mg) in a yield of 56%: tR 0.64 min (LC-1); ESI-MS (+/−): m/z 241.49 [M+H]+/239.37 [M−H]−.

1. filtrationthe precipitated product is filtered off