HCID 18957055, compound → HCID 15640829, compound

Participants

Reaction Steps

48.7 g of 7-oxo-8-phenyl-7H-pyrido[1,2-b]thieno[2,3-d]-pyridazine-10-carboxylic acid were added to a methanolic potassium hydroxide solution (prepared from 72 g of potassium hydroxide and 640 ml of methanol) and the mixture was heated to boiling under reflux for about 24 hours. The reaction mixture was evaporated to half in a vacuum, treated with 80 ml of water and adjusted to pH 1 by the addition of 1N hydrochloric acid. The separated crystals were filtered off under suction, washed with water and dried in a vacuum. There was obtained 48.6 g of 2-(3-cyano-2-thienyl)-1,6-dihydro-6-oxo-5-phenylnicotinic acid as yellow crystals with a m.p. of 255°-257° (methanol/N,N-dimethylformamide).

Provenance & Evidence