HCID 11128927, compound → HCID 10967168, compound

Participants

Reaction Steps

A solution of ethyl 1-tert-butoxycarbonyl-1,4,5,6-tetrahydropyrazine-2-carboxylate (69.0 g) in acetic acid (AcOH, 500 ml) was subjected to catalytic reduction using platinum dioxide (4.0 g) at 40° C. in hydrogen at 3 atm for 4 hours. The catalyst was removed by filtration, and the filtrate was concentrated in vacuo. The residue was dissolved in H2O (800 ml) and the solution was washed with Et2O (500 ml×2). To the aqueous layer was added NaHCO3 to adjust the pH of the solution to 8 and the solution was extracted with AcOEt (800 ml×2). The combined organic layer was washed with saturated aqueous NaHCO3 solution and brine, dried over MgSO4 and concentrated in vacuo to give 62.8 g of ethyl 1-tert-butoxycarbonyl- piperazine-2-carboxylate as an oil.

Provenance & Evidence