Hydrazine hydrate (1:1) → HCID 2810177, compound

Participants

Reaction Steps

To a solution of 5-Amino-4-oxo-3-phenyl-3,4-dihydro-thieno[3,4-d]pyridazine-1-carboxylic acid ethyl ester (20 g, 0.063 mol, prepared as described in example 25) in ethanol (400 ml) was added hydrazine hydrate (3.3 g, 0.066 mol). The reaction mixture was stirred at reflux temperature for 6 h at which time an additional portion of hydrazine hydrate (3.3 g, 0.066 mol) was added and the resulting mixture was stirred for an additional 66 h at reflux temperature. An additional portion of hydrazine hydrate (1.5 g, 0.03 mol) was added and the reaction mixture was stirred for an additional 16 h at reflux temperature. The reaction mixture was cooled and the precipitated was filtered off, washed with small portions of ethanol and dried in vacuo at 50° C. for 18 h which afforded 17.9 g (94%) of the title compound as a solid.

Provenance & Evidence