Trifluoroacetic acid → Methyl 8-aminopyrazolo[5,1-a]isoquinoline-7-carboxylate

Participants

Reaction Steps

TFA (3 mL) was added to a solution of methyl 8-[bis-(tert-butoxycarbonyl)amino]-pyrazolo[5,1-a]isoquinoline-7-carboxylate (Intermediate 7, 0.280 g) in DCM (3 mL) and the reaction mixture was stirred at room temperature for 2 hours. The mixture was stirred with saturated aqueous sodium bicarbonate solution for 30 minutes and then the organic layer was separated, dried (MgSO4) and filtered. The filtrate was concentrated in vacuo and the residue was purified by chromatography on silica, eluting with a mixture of ethyl acetate and cyclohexane with a gradient of 0-100% to give methyl 8-aminopyrazolo[5,1-a]isoquinoline-7-carboxylate (0.140 g) as a glass.

Provenance & Evidence