Triethylamine → 1-[6,7-Dimethoxyphthalazin-1-yl]piperid-4-one trimethylene ketal

Participants

Reaction Steps

4-Piperidone trimethylene ketal hydrochloride (20 g), 1-chloro-6,7-dimethoxyphthalazine (10 g), triethylamine (50 ml) and ethanol (300 ml) were heated together under reflux for 70 hours. The resulting mixture was evaporated in vacuo and the residue was partitioned between chloroform (2×100 ml) and water (60 ml). The chloroform extracts were combined, dried (MgSO4) and evaporated in vacuo to give a crude brown oil which on trituration with ethyl acetate (100 ml) at boiling point gave 1-[6,7-dimethoxyphthalazin-1-yl]piperid-4-one trimethylene ketal (11 g), m.p. 194°-6°. A second crop of the product (3 g) was obtained by evaporating the ethyl acetate trituration liquors.

Provenance & Evidence