Ammonia → 4,5-Dihydro-5-methyl-6-(4-(4-oxo-1(4H)-pyridinyl)phenyl)-3(2H)-pyridazinone

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Reaction Steps

A stirred mixture of 6-(4-aminophenyl)-5-methyl-4,5-dihydro-3(2H)-pyridazinone (1.0 g), 4H-pyran-4-one (0.52 g), water (20 ml), and concentrated hydrochloric acid (0.41 ml) was heated under reflux for 31/2 hours. The resultant solid was dissolved in the minimum of hot water and the solution was neutralised with aqueous ammonia to give the crude product, 1.16 g, m.p. 249-256° C. The product was recrystallised first from water to which a little 2N NaOH was added, and then from water alone to give the pure title compound, 0.82 g, m.p. 254-256° C. (after melting and resolidifying at about 150° C.).

Provenance & Evidence