Sulfuric Acid → HCID 20367582, compound

Participants

Reaction Steps

A stirred mixture of 10.5 g of 1-methyl-3-(4-cyano-3-(1-pyrrolidinyl)-5-isothiazolyl)urea and 15 ml of sulfuric acid was heated at 100° during 21/2 hours. The mixture was poured into 250 ml of stirred ice-water and neutralized by slow addition of saturated sodium bicarbonate solution. The separated solid was collected by filtration. The filtrate was allowed to stand for a short time, and filtered again. The collected solid was found to be a mixture of the desired product and unreacted starting material. A third solid that formed when the filtrate was allowed to stand overnight was isolated by filtration to give 4.6 g of 1-methyl-3-(4-carbamoyl-3-(1-pyrrolidinyl)-5-isothiazolyl)urea, which darkened at 241°, then decomposed at 257°. The nmr spectrum was consistent with the assigned structure.

Provenance & Evidence