Hydrochloric Acid → HCID 178470042, compound

Participants

Reaction Conditions

Reaction Steps

5-Ethoxycarbonylamino-1,2,3-thiadiazole-4-carboxylic Acid. A suspension of sodium thiocyanate (24.30 g, 0.30 mole) in acetonitrile (120 ml), maintained at 19° C., was treated dropwise over 22 minutes with a solution of ethyl chloroformate (28.7 ml, 0.30 mole) in acetonitrile (25 ml). The resultant mixture was stirred for 25 minutes at 20° C. and then ethyl diazoacetate (31.5 ml, 0.30 mole) was added. After stirring for 24 hours, 6.0 N hydrochloric acid (300 ml) was added with cooling. Acetonitrile solvent was removed in vacuo and the residual aqueous suspension was extracted several times with ether. Combined ether extracts were washed with water, dried (Na2SO4) and evaporated to leave 51.0 g of ethyl 5-ethoxy-carbonylamino-1,2,3-thiadiazole-4-carboxylate. This ester was hydrolyzed by refluxing for 6 hours in a mixture of ethanol (80 ml) and aqueous 6 N hydrochloric acid (400 ml) to yield the title acid; m.p. 179°-180° dec. after crystallization from nitromethane.

Provenance & Evidence