N-bromobutanimide → 7-(tert-Butyl) 1-methyl 3-bromo-5,6-dihydroimidazo[1,5-a]pyrazine-1,7(8H)-dicarboxylate

Participants

Reaction Steps

The Intermediate 1G (3.20 g, 11.38 mmol) was dissolved in acetonitrile and NBS (2.43 g, 13.65 mmol) was added. The reaction mixture was stirred at room temperature overnight. The mixture was concentrated and partitioned between ethyl acetate and water. The organic layer was washed with brine, dried over anhydrous Na2SO4, filtered and concentrated to give a yellow solid. The solid was dissolved in DCM and passed through a silica gel plug, eluting with 10% methanol in DCM to give product Intermediate 1H as a yellow solid (3.90 g, 95%).

Provenance & Evidence