Water → 4-bromo-2H-phthalazin-1-one

Participants

Reaction Steps

A mixture of phthalhydrazide (3.2 g) and phosphorus pentabromide (19.0 g) was heated with stirring in carbon tetrabromide (50 g) at 125° for 16 hours. The cooled mixture was poured into water (50 cm3) and the product collected by filtration. The solid product was chromatographed on silica (Merck "MK 60.9385" [Trade Mark]) eluting with diethyl ether:dichloromethane, 1:3 by volume. Combination and evaporation of appropriate fractions afforded the title compound, m.p. 268°-271° (1.5 g).

Provenance & Evidence