1,3-Dibromopropane → 4H,5H,6H,7H-pyrazolo(1,5-a)pyrimidine

Participants

Reaction Steps

5-Aminopyrazole (10 g) and 1,3-dibromopropane (13.4 ml) were added to 1,4-dioxane (20 ml) under stirring at ambient temperature. Triethylamine (40.1 ml) was added thereto. The mixture was refluxed under stirring for 4 hours. The reaction mixture was cooled to 0°-5° C. in an ice-bath and stirred for 30 minutes. An insoluble material was filtered off, and the filtrate was evaporated under reduced pressure to give 4,5,6,7-tetrahydropyrazolo[1,5-a]pyrimidine (5.1 g).

Provenance & Evidence