Sodium hydride → 1,1-Dimethylethyl 4-[(2,6-dichloro-4-pyrimidinyl)amino]-1-piperidinecarboxylate

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Reaction Steps

To a solution of 4-amino-piperidine-1-carboxylic acid tert-butyl ester (4.0 g, 20.0 mmol, 1.3 equiv) in dry DMF (100 mL) under Ar was added sodium hydride (1.01 g, 23.1 mmol, 1.5 equiv; 55% free-flowing powder moistened with oil) and the reaction mixture stirred at rt. After 2 h, 2,4,6-trichloro-pyrimidine (2.82 g, 15.4 mmol, 1.0 equiv; commercially available) was added and the mixture stirred at rt for 48 h. The solvent was removed under reduced pressure and the crude reaction product extracted from a solution of 1 M NaOH (100 mL) with ethyl acetate (3×100 mL). The combined organic phases were dried over MgSO4, concentrated by evaporation under reduced pressure and the crude material purified with silica column chromatography using a MPLC system (CombiFlash Companion, Isco Inc.) eluting with a gradient of heptane/ethyl acetate to provide 3.1 g (57%) of the title compound. 1H NMR (400 MHz, DMSO): δ 1.24-1.33 (m, 2H), 1.40 (s, 9H), 1.78-1.85 (m, 2H), 2.86-2.96 (m, 2H), 3.49-3.97 (m, 3H), 6.47 (s, 1H). MS (ISP): 347.3 [M+H]+.

Provenance & Evidence