Phosphorus oxychloride → ethyl 4-chloro-1-ethyl-1H-pyrazolo[3,4-b]pyridine-5-carboxylate

Participants

Reaction Conditions

Reaction Steps

A mixture of diethyl {[(1-ethyl-1H-pyrazol-5-yl)amino]methylidene}propanedioate (15 gm, 0.0533 mole) (example 2) and phosphorous oxy chloride (76.64 ml, 0.7998 mole) was heated at 110-120° C. under stirring for about 4 hours under argon atmosphere. The reaction mixture was cooled and then poured drop wise into ice water. A pale yellow solid separated which was filtered. The solid was first washed twice with ice cold water and then finally with hexane and dried over vacuum.

Provenance & Evidence