Phosphorus oxychloride → 5-Chloro-8-ethyl-8H-pyrazolo[4',3':5,6]pyrido[3,4-e][1,2,4]-triazolo[1,5-a]pyrimidine

Participants

Reaction Steps

25.5 g. of 8-ethyl-4H-pyrazolo[4',3':5,6]pyrido[3,4-e]-[1,2,4]triazolo[1,5-a]pyrimidin-5(8H)-one (0.1 mol.) are refluxed in 100 ml. of phosphorus oxychloride for 12 hours. After this time, the excess phosphorus oxychloride is distilled off in vacuo, the residue is treated with dry acetone and filtered off. 25 g. of 5-chloro-8-ethyl-8H-pyrazolo[4',3':5,6]pyrido[3,4-e][1,2,4]triazolo[1,5-a]-pyrimidine are obtained, yield 92%; m.p. 196°-197°.

Provenance & Evidence