Hydrochloric Acid → tert-Butyl 3-amino-4,6-dihydropyrrolo[3,4-c]pyrazole-5(1H)-carboxylate

Participants

Reaction Steps

To a solution of anhydrous hydrazine (0.082 mL) in ethanol (6.5 mL) was added hydrogen chloride (1.43 mL, 2N solution in diethyl ether). The reaction mixture was stirred for 5 min, then tert-butyl 3-cyano-4-oxopyrrolidine-1-carboxylate was added and the mixture heated to reflux. After 1 h the mixture was cooled to ambient temperature and diluted with a mixture of ethyl acetate and saturated aqueous sodium bicarbonate solution (1:1, 20 mL). The layers were separated and the aqueous phase extracted with ethyl acetate (3×15 mL). The combined organic phases were dried over anhydrous sodium sulfate, filtered and evaporated in vacuo. The residue was purified on a Biotage Horizon® system (silica gel, 0 to 100% ethyl acetate/hexanes followed by 0 to 20% methanol/ethyl acetate gradient) to give the title compound. LC/MS 225.2 (M+1).

Provenance & Evidence