Potassium Hydroxide → HCID 19972722, compound

Participants

Reaction Steps

A solution of 38.22 g of silver nitrate in 75 ml of water was added dropwise, under stirring, at 20°-25° C., to a solution of 22.5 g of 8-formyl-4-oxo-3-phenyl-4H-1-benzopyran (prepared as described by G. Atassi et al., Eur. J. Med. Chem. - Chim. Ter. 20, 393 (1985)) in 150 ml of 85% ethanol and 450 ml of N,N-dimethylformamide. Then, a solution of 32.67 g of 85% potassium hydroxide in 195 ml of water was added dropwise under stirring at 15°-20° C. After additional stirring at room temperature, the reaction mixture was filtered by suction; the mother liquor was acidified with 37% hydrochloric acid and diluted with 1.2 l of water. Filtration by suction and washing with water to neutrality gave the title compound as a crude. The crude was suspended in 150 ml of ethyl acetate and stirred with 444 ml of 0.3M aqueous sodium hydrogen carbonate solution until clear layers were obtained. The aqueous layer was washed with 75 ml of ethyl acetate, then made acidic with 37% hydrochloric acid, filtered and dried at 60°-65° C. to give 19, 12 g of the title compound that melted at (215) 218° C. A sample, crystallized from ethanol, showed the same melting point, m.p. (215) 218° C.

Provenance & Evidence