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

Participants

Reaction Steps

To a stirred solution of 5-benzyloxy-6-hydroxy-2-(1-phenyl-cyclopentylmethyl)-pyrimidine-4-carboxylic acid cyclopropyl-(2-hydroxyethyl)-amide (285) (300 mg, 0.62 mmol) in dichloromethane (30 mL) were added triphenyl phosphine (242 mg, 0.92 mmol) and diisopropyl azodicarboxylate (0.2 mL, 1.23 mmol) at room temperature. Stirring was continued for 10 min at room temperature. The reaction mixture was concentrated under reduced pressure to get a crude product, which was purified by Combi-Flash column (triphenyl phosphine oxide was eluted in ethyl acetate and the product was eluted at 2% methanol in dichloromethane). It was again purified by preparative TLC plate to remove traces of triphenyl phosphine oxide (mobile phase: ethyl acetate) and 9-benzyloxy-2-cyclopropyl-6-(1-phenyl-cyclopentylmethyl)-3,4-dihydro-2H-pyrazino[1,2-c]pyrimidine-1,8-dione (286) (180 mg, 62.3%) was obtained as a white sticky solid.

Provenance & Evidence