Phosphorus oxychloride → 4-Chloro-1H-pyrazolo[3,4-d]pyrimidine

Participants

Reaction Steps

31.1 g. of 4-hydroxypyrazolo[3,4-d]pyrimidine are heated at reflux with 200 ml. of phosphorous oxychloride for 12 hours. The excess phosphorous oxychloride is distilled off and the residue is boiled with benzene. After distilling off the benzene and trituration with petroleum ether, there remain 15.8 g. of 4-chloropyrazolo[3,4-d]pyrimidine as light yellow crystals, m.p. 94°-96°. This product is pure enough for further use.

Provenance & Evidence