Butylamine → Cartazolate

Participants

Reaction Steps

To a solution of 50.8 g. of 4-chloro-1-ethyl-1H-pyrazolo[3,4-b]pyridine-5-carboxylic acid ethyl ester (0.2 mol.) in 200 ml. of benzene, 29.2 g. of n-butylamine (0.4 mol.) are added. The mixture is kept at 50° for 5 hours. Then the separated butylamine hydrochloride is filtered under suction and the filtrate is evaporated in vacuo to dryness. The residual 4-butylamino-1-ethyl-1H-pyrazolo[3,4-b]pyridine-5-carboxylic acid ethyl ester is recrystallized from hexane, m.p. 82°-83°, yield 53 g. (91.5%).

Provenance & Evidence