Trifluoroacetic acid → hexahydro-2H-pyrazino[1,2-a]pyrazin-1(6H)-one

Participants

Reaction Steps

To a solution of 1-(1,1-dimethylethyl) 3-ethyl 4-[2-({[(1,1-dimethylethyl)oxy]carbonyl}amino)ethyl]-1,3-piperazinedicarboxylate (D77, 2.492 g, 6.21 mmol) in dichloromethane (30 mL) kept at 0° C. was added TFA (10 mL) dropwise. The solution was kept at 0° C. for 2 h, and then at room temperature for 6 h. The deprotected product was isolated by SCX and the resulting solution was evaporated at 50° C. to induce cyclization. The target product was purified by reverse phase chromatography (Oasis HLB 6 g×4 columns, eluted with water), obtaining 372 mg of the title compound.

Provenance & Evidence