2,4-dichloro-5H,6H,7H-cyclopenta(d)pyrimidine → tert-butyl 4-(2-chloro-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-ylamino)piperidine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

A mixture of 2,4-dichloro-6,7-dihydro-5H-cyclopentapyrimidine (2.71 g, 14.34 mmol, 1.0 equiv) and 4-amino-piperidine-1-carboxylic acid tert-butyl ester (3.45 g, 17.20 mmol, 1.2 equiv) in anhydrous DMF (40 mL) was heated to 60° C. for 18 h. The organic phase was concentrated under reduced pressure and the crude reaction mixture extracted from a solution of 1 M NaOH (100 mL) with ethyl acetate (3×50 mL). The combined organic phases were dried over MgSO4 and the product purified with column chromatography on silica eluting with a gradient of heptane/ethyl acetate (14:3→1:1) providing 2.34 g (47%) of the title compound. 1H NMR (300 MHz, DMSO): δ 1.32-1.43 (m, 2H), 1.39 (s, 9H), 1.79-1.82 (m, 2H), 2.0 (quint, J=7.5 Hz, 2H), 2.61 (t, J=7.5 Hz, 2H), 2.70 (t, J=7.5 Hz, 2H), 2.80-2.88 (m, 2H), 3.93-3.98 (m, 2H), 4.04-4.13 (m, 1H), 7.07 (d, J=8.0 Hz, 1H). 13C NMR (75 MHz, DMSO): δ 21.12, 26.42, 28.04, 31.17, 33.19, 42.55, 47.12, 78.53, 114.87, 153.84, 157.95, 159.02, 172.18. MS (ISP): 353.1 [M+H]+.

Provenance & Evidence