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

Participants

Reaction Steps

To a stirred solution of 5-(benzyloxy)-6-hydroxy-N-(2-hydroxyethyl)-N-isopropyl-2-(2-methyl-2-phenylpropyl)pyrimidine-4-carboxamide (58) (35 mg, 75.5 μmol, Eq: 1.00) in dichloromethane (5.00 ml) was added triphenylphosphine (29.7 mg, 113 μmol, Eq: 1.5) at room temperature and the reaction mixture was stirred for 10 min. Then diisopropyl azodicarboxylate (22.9 mg, 22.0 μl, 113 μmol, Eq: 1.5) was added and the reaction mixture was stirred for 18 hrs at room temperature. The reaction mixture was concentrated on a rotary evaporator and chromatographed (silica gel, gradient, 2 to 5% methanol-dichloromethane) to obtain 9-(benzyloxy)-2-isopropyl-6-(2-methyl-2-phenylpropyl)-3,4-dihydro-1H-pyrazino[1,2-c]pyrimidine-1,8(2H)-dione (59) (18 mg, 53.5% yield).

Provenance & Evidence