Water → HCID 13749195, compound

Participants

Reaction Steps

5-Acetyl-4-chloro-1-ethyl-1H-pyrazolo[3,4-b]pyridine (4.60 g) was refluxed for 2 hours in 450 ml of glacial acetic acid containing 15 g of hydroxylamine hydrochloride and 1.0 g of p-toluenesulfonic acid monohydrate. At the end of this time the reaction volume was reduced to ca. 200 ml under reduced pressure and then it was poured into 800 ml of water. The amorphous precipitate was filtered off and purified over 230-400 mesh silica gel (5% ethyl acetate/dichloromethane). The appropriate fractions were combined and evaporated and the resultant crystalline product was washed with pentane to give 1.75 g, mp 181°-182° C.

Provenance & Evidence