Dichloromethane → 3-Nitro-4,5,6,7-tetrahydropyrazolo[1,5-a]pyrimidine

Participants

Reaction Conditions

Reaction Steps

A solution of 51.2 g (0.4 moles) 3-amino-4-nitropyrazole in 650 ml dried DMF is slowly added by drops to a suspension of 10 g (0.4 moles) sodium hydride in 200 ml dried DMF. After the reaction is concluded, 121 g (0.6 moles) 1,3-dibromopropane in 250 ml DMF are added. The mixture is then heated for 5 hours accompanied by reflux. After cooling, the preparation is reduced to dryness. When the residue is treated with 300 ml dichloromethane and subsequently cooled to 0° C. the product is precipitated out together with NaBr. The raw product is recrystallized from 1200 ml ethanol. 59 g (38%) ocher-colored crystals with a melting point of 251°-252° C. are obtained.

Provenance & Evidence