Ethyl Acetate → 9-benzyloxy-6-[1-(4-chlorophenyl)-cyclopentylmethyl]-2-(tetrahydro-pyran-4-yl)-3,4-dihydro-2H-pyrazino[1,2-c]pyrimidine-1,8-dione

Participants

Reaction Steps

5-Benzyloxy-2-[1-(4-chlorophenyl)-cyclopentylmethyl]-6-hydroxypyrimidine-4-carboxylic acid (2-hydroxyethyl)-(tetrahydro-pyran-4-yl)-amide (334) (90 mg, 0.16 mmol) and triphenylphosphine were taken up in dichloromethane (3 ml) at room temperature and diisopropyl azodicarboxylate was added slowly. Stirring was continued for 1 h while silica thin layer chromatography was performed (ethyl acetate:hexane=1:1, Rf=0.6). Dichloromethane (15 ml) was added to the reaction mixture, which was thereafter washed with water (10 ml) and brine (10 ml). The organic part was dried and concentrated under reduced pressure. The obtained residue was purified by nor mal silica gel (100-20 mesh) column chromatography using 30% ethyl acetate in hexane to get 9-benzyloxy-6-[1-(4-chlorophenyl)-cyclopentylmethyl]-2-(tetrahydro-pyran-4-yl)-3,4-dihydro-2H-pyrazino[1,2-c]pyrimidine-1,8-dione (335) (50 mg, 60%; 2 steps yield).

Provenance & Evidence