Sulfuric Acid → HCID 18550659, compound

Participants

Reaction Steps

A solution of 5.6 g of 1-methyl-3-(4-cyano-3-ethoxy-5-isothiazolyl)urea (from Example I) in 10 ml of concentrated sulfuric acid was heated at 50° during 1.5 hours. The reaction mixture was poured into 200 ml of ice-water and stirred for one half hour. The resultant precipitate was collected by filtration and was allowed to air-dry overnight. The solid was slurried with 50 ml of saturated sodium bicarbonate solution. The resulting white solid was collected by filtration and recrystallized from ethanol to give 4.3 g of 1-methyl-3-(4-carbamoyl-3-ethoxy-5-isothiazolyl)urea, m.p. 240°-241°.

Provenance & Evidence