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

Participants

Reaction Conditions

Reaction Steps

To a solution of (R)-4-chloro-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidine (0.5 g, 3.0 mmol) in NMP (10 mL) was added 1-Boc-piperazine (1.2 g, 2.17 mmol). The mixture was stirred at 110° C. overnight. After cooling, the mixture was diluted with ethyl acetate (200 mL) and washed with water (6×100 mL). The organic phase was dried and concentrated. The residue was purified by silica gel chromatography, eluting with ethyl acetate to afford (R)-tert-butyl 4-(5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-yl)piperazine-1-carboxylate (0.806 g, 86%). 1H NMR (CDCl3, 400 MHz) δ 8.48 (s, 1H), 3.68 (m, 2H), 3.60-3.40 (m, 7H), 2.84 (m, 2H), 2.30 (m, 1H), 1.67 (m, 1H), 1.49 (m, 9H), 1.18 (d, J=6.8 Hz, 3H). MS (APCI+) [M+H]+319.

Provenance & Evidence