Acetic Acid → 8-Chloro-1,4-dihydro-[1]-benzopyrano[4,3-c]pyrazole

Participants

Reaction Steps

A solution of 6-chloro-3,4-dihydro-3-dimethylaminomethylene-4-oxo-2H-1-benzopyran (1.188 g), hydrazine hydrate (0.325 g), and acetic acid (0.39 g) in a mixture of chloroform (10 ml) and methanol (20 ml) was stirred overnight at room temperature and then evaporated in vacuo. The residual solid was washed with water, dried, and recrystallized form ethyl acetate to give 8-chloro-1,4-dihydro-[1]-benzopyrano[4,3-c]pyrazole (0.95 g).

Provenance & Evidence