Hydrochloric Acid → 6,7-Dimethoxyquinazoline-2,4(1H,3H)-dione

Participants

Reaction Steps

21 g of 2-Amino-4,5-dimethoxy benzoic acid was dissolved in 40 ml of tetrahydrofuran and 40 ml of water. To this solution 10 ml of conc. hydrochloric acid and 11.6 g of potassium cyanide were added. It was left to stand overnight and 50 g of sodium hydroxide was added. After stirring for 2 hours, the resulting precipitate was isolated by filtration. The precipitate was dissolved in 1000 ml of water and acidified with 50% sulfuric acid. The resulting crystal was isolated by filtration and 13.0 g of the desired compound was obtained. m.p. 320° C. (decomp).

Provenance & Evidence