5N-Boc-3-amino-4,6-dihydro-1H-pyrrolo[3,4-c]pyrozole

175463-32-8

398491-59-3

The general procedure for the synthesis of 3-amino-5-tert-butoxycarbonyl-pyrrolo[3,4-C]pyrazole from 1-Boc-3-cyano-4-pyrrolidinone was as follows: 1-Boc-3-cyano-4-pyrrolidinone (4.5 g, 43 mmol) was dissolved in anhydrous ethanol (250 ml), and the reaction was stirred for 3 h at 60 °C. After completion of the reaction, the solvent was removed by distillation under reduced pressure. Saturated sodium bicarbonate solution (50 ml) was added to the residue until the solid was completely dissolved. Subsequently, the extracted organic phase was removed by evaporation under reduced pressure to give the white solid product 1b (6.3 g, 66% yield). The product did not require further purification and could be used directly in the next step of the reaction.