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

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Reaction Conditions

Reaction Steps

The solution of 4-chloro-6,7-dihydro-5H-cyclopenta[d]pyrimidine 1-oxide (2.93 g, 17.2 mmol) in acetic anhydride (50 mL) was added dropwise to the acetic anhydride (50 mL) at 50° C. After addition, the mixture was stirred at 110° C. for 2 hour. After cooling, the solvent was removed and the residue was treated with toluene and hexanes (1:1, 200 mL). The mixture was stirred and then the solvent was removed. The residue was subject to chromatography on silica gel, eluted by hexanes/ethyl acetate (4:1-3:1) to afford the 4-chloro-6,7-dihydro-5H-cyclopenta[d]pyrimidin-7-yl acetate (2.3 g, 63%). 1H NMR (CDCl3, 400 MHz) δ 8.92 (s, 1H), 6.20-6.16 (m, 1H), 3.20-3.10 (m, 1H), 3.03-2.93 (m, 1H), 2.76-2.67 (m, 1H), 2.20-2.05 (m, 4H).

Provenance & Evidence