tert-Butyl piperazine-1-carboxylate → tert-butyl 4-(7-acetoxy-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-yl)piperazine-1-carboxylate

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Reaction Steps

To a solution of 4-chloro-6,7-dihydro-5H-cyclopenta[d]pyrimidin-7-yl acetate (1.15 g, 5.4 mmol) in NMP (4 mL) and TEA (0.5 mL) was added 1-Boc-piperazine (1.05 g, 5.64 mmol). The mixture was microwaved at 100° C. for 30 minutes and then diluted with ethyl acetate (200 mL) and washed with water (6×100 mL). The organic phase was dried and concentrated. The residue was subject to chromatography on silica gel, eluting by hexanes/ethyl acetate (2:1-1:1) to afford the tert-butyl 4-(7-acetoxy-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-yl)piperazine-1-carboxylate (1.47 g, 75%). 1H NMR (CDCl3, 400 MHz) δ 8.56 (s, 1H), 5.99-5.96 (m, 1H), 3.78-3.73 (m, 2H), 3.53-3.50 (m, 2H), 3.15-3.07 (m, 1H), 2.99-2.92 (m, 1H), 2.63-2.54 (m, 1H), 2.04-1.93 (m, 1H), 1.48 (s, 9H). MS (APCI+) [M+H] +363.

Provenance & Evidence