Acetic Anhydride → (5R)-4-chloro-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidin-7-yl acetate

Participants

Reaction Steps

A solution of the (R)-4-chloro-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidine 1-oxide (5.5 g, 29.8 mmol) in Ac2O (40.5 mL, 429 mmol) was heated to 110° C. for 3 hours. After cooling, the acetic anhydride was evaporated, and the resulting residue was taken up in DCM. This solution was added to a stirring cold solution of saturated NaHCO3. The layers were extracted with DCM, dried MgSO4, filtered, and concentrated. The crude oil was chromatographed (Biotage) eluting with 20% EtOAc/hexane, to provide (5R)-4-chloro-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidin-7-yl acetate (3.0 g, 44.4%).

Provenance & Evidence