Ethyl Acetate → 9-benzyloxy-6-[1-(2,5-dichlorophenyl)-cyclopentylmethyl]-2-isopropyl-3,4-dihydro-2H-pyrazino[1,2-c]pyrimidine-1,8-dione

Participants

Reaction Steps

To a stirred solution of 5-benzyloxy-2-[1-(2,5-dichlorophenyl)-cyclopentylmethyl]-6-hydroxypyrimidine-4-carboxylic acid (2-hydroxyethyl)-isopropylamide (207) (125 mg, 0.22 mmol) in tetrahydrofuran (5 mL) were added triphenyl phosphine (117 mg, 0.45 mmol) and diisopropyl azodicarboxylate (0.09 mL, 0.45 mmol) at room temperature, a yellow clear solution was formed, after 5 min it turned into a light yellow hazy solution. The solution was stirred for 2 h at room temperature. Silica thin layer chromatography was performed (100% ethyl acetate, Rf=0.3). The mixture was concentrated under reduced pressure to get a crude product, which was purified by a CombiFlash column (eluted at 2-5% methanol in dichloromethane) to get 9-benzyloxy-6-[1-(2,5-dichlorophenyl)-cyclopentylmethyl]-2-isopropyl-3,4-dihydro-2H-pyrazino[1,2-c]pyrimidine-1,8-dione (208) (40 mg, 33.07%) as a white sticky solid.

Provenance & Evidence