Triphenylphosphine → 9-(benzyloxy)-6-((1-(4-chlorophenyl)cyclopentyl)methyl)-2-(1-phenylethyl)-3,4-dihydro-1H-pyrazino[1,2-c]pyrimidine-1,8(2H)-dione

Participants

Reaction Steps

To a stirred solution of 5-(benzyloxy)-2-((1-(4-chlorophenyl)cyclopentyl)methyl)-6-hydroxy-N-(2-hydroxyethyl)-N-(1-phenylethyl)pyrimidine-4-carboxamide (36) (158 mg, 270 μmol, Eq: 1.00) in dichloromethane (15 ml) at room temperature was added triphenylphosphine (106 mg, 404 μmol, Eq: 1.5). The reaction mixture was stirred for 10 min. Then diisopropyl azodicarboxylate (81.8 mg, 78.6 μl, 404 μmol, Eq: 1.5) was added. The reaction mixture was stirred for 18 hrs, concentrated, and chromatographed (silica gel, gradient 0 to 5% methanol-dichloromethane) to obtain 9-(benzyloxy)-6-((1-(4-chlorophenyl)cyclopentyl)methyl)-2-(1-phenylethyl)-3,4-dihydro-1H-pyrazino[1,2-c]pyrimidine-1,8(2H)-dione (37) (colorless of 1,120 mg, 211 μmol, 78.4% yield).

Provenance & Evidence