Sodium Hydroxide → HCID 20564185, compound

Participants

Reaction Steps

Warm a suspension of 7-methoxycarbonyl-(1H,3H,5H)-(1)-benzopyrano-(2,3-d)-pyrimidine-4-one-2-thione (5 g.) in 1 N-sodium hydroxide (25 ml.) until a clear solution is formed and continue the warming for an additional 1/2 hour. Filter the solution and acidify the filtrate with 2 N sulfuric acid. Filter and wash the solids with water, isopropanol and then ether. Dry the washed solid to obtain. 7-carboxy-2,4-(1H,3H,5H)-(1)-benzopyrano-(2,3-d)-pyrimidine-4-one-2-thione.

Provenance & Evidence