Hydrazine hydrate (1:1) → 6-Chloroimidazo[1,2-b]pyridazine-8-carboxylic acid hydrazide

Participants

Reaction Steps

To a solution of crude 6-chloro-imidazo[1,2-b]pyridazine-8-carboxylic acid ethyl ester (5.00 g, “22 mmol”) in 40 mL of ethanol at 0-5° C. was added 10 mL of hydrazine hydrate. Yellow solid immediately precipitated. After 15 min. at 0-5° C., the solid was isolated by Buchner filtration, rinsing well with ice-cold ethanol (250 mL total) and dried by sucking air through then in vacuo. A small amount of additional solid precipated from the filtrate and was isolated and dried similarly to the first crop. A total of 2.38 g (57% over three steps) of 6-chloro-imidazo[1,2-b]pyridazine-8-carboxylic acid hydrazide was isolated as a yellow solid.

Provenance & Evidence