Ethanol → HCID 22112748, compound

Participants

Reaction Steps

To a solution of 5-amino-3-(4-methoxy-phenyl)-4-oxo-3,4-dihydro-thieno[3,4-d]pyridazine-1-carboxylic acid ethyl ester (3 g, 8.69 mmol, prepared in example 23) in a mixture of ethanol (50 ml) and water (25 ml) was added sodium hydroxide (0.38 g, 9.55 mmol). The resulting reaction mixture was stirred for 2.5 h at room temperature. Water (150 ml) was added, undissolved matter was filtered off. The aqueous phase was washed with diethyl ether (2×100 ml), pH was adjusted to pH=4 by addition of concentrated hydrochloric acid. The precipitate was filtered off and washed with water (2×50 ml), heptane (2×50 ml) and dried in vacuo at 50° C. for 18 h affording 2.3 g (83%) of the title compound as a solid.

Provenance & Evidence