Triphenylphosphine → 9-benzyloxy-6-[1-(4-bromophenyl)-cyclopentylmethyl]-2-isopropyl-3,4-dihydro-2H-pyrazino[1,2-c]pyrimidine-1,8-dione

Participants

Reaction Steps

To a mixture of 5-benzyloxy-2-[1-(4-bromophenyl)-cyclopentylmethyl]-6-hydroxypyrimidine-4-carboxylic acid (2-hydroxyethyl)-isopropylamide (233) (0.7 g, 1.23 mmol) and triphenyl phosphine (0.807 g, 3.08 mmol) in dr y dichloromethane (10 mL) was added diethyl azidocarboxylate (0.58 mL, 3.69 mmol) at room temperature. The reaction mixture was stirred at room temperature for 2 h. After completion, the solvent was evaporated and the crude product was purified by 100-200 silica gel column chromatography using 2% methanol in dichloromethane as the eluent to give 9-benzyloxy-6-[1-(4-bromophenyl)-cyclopentylmethyl]-2-isopropyl-3,4-dihydro-2H-pyrazino[1,2-c]pyrimidine-1,8-dione (234) (0.40 g, 59%) as a white solid.

Provenance & Evidence