Tetrahydrofuran → 4-chloro-1H-pyrazolo[3,4-d]pyrimidin-6-amine

Beteiligte Stoffe

Reaktionsschritte

To a mixture of 2-amino-4,6-dichloropyrimidine-5-carboxaldehyde (2) (150 g, 0.785 mol), THF (2.7 L) and triethylamine (125 ml) was added anhydrous hydrazine (25.5 ml in 600 ml of water) drop wise over 25 min. Alternatively, hydrazine monohydrate can be used instead of anhydrous hydrazine. The mixture was stirred for 1 h. The solids were filtered off and the filtrate was evaporated to remove about 80% of the THF. Water was added and the resulting precipitate was filtered and dried under vacuum. The solid was then dissolved in a minimum volume of hot DMF and precipitate by addition of water to provide 112 g (85% yield) of 4-chloro-6-aminopyrazolo[3,4-d]pyrimidine (3).

Herkunft & Nachweise