Sodium Bicarbonate → Allyl 2-amino-6-(cyanomethyl)-pyrazolo[1,5-a]pyrimidine-3-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a suspension of allyl 3,5-diamino-1H-pyrazole-4-carboxylate 3 (63.49 g, 348.5 mmol) in a mixture of DMSO (340 mL) and water (340 mL), was added 3-(dimethoxymethyl)-4,4-dimethoxy-butanenitrile (Scheme 3, below) (85 g, 418.2 mmol), followed by para-toluene Sulfonic acid hydrate (1) (11.27 g, 59.24 mmol). The reaction mixture was heated to 85° C. and stirred overnight. The reaction mixture was cooled with an ice bath. The mixture was diluted with EtOAc (680 mL) and a saturated aqueous solution of NaHCO3 (1.36 L). The precipitate was filtered and rinsed with water, then with a mixture of water and EtOAc. The brown solid was dried under vacuum to give allyl 2-amino-6-(cyanomethyl)-pyrazolo[1,5-a]pyrimidine-3-carboxylate 4c as a brown solid (55.94 g, 62% yield).

Provenance & Evidence