N-(1-benzylpiperidin-4-yl)-2,2,2-trifluoroacetamide → 2,2,2-trifluoro-N-(piperidin-4-yl)acetamide

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Reaction Steps

Using 4 g of 10% palladium-on-carbon (50% hydrous) as a catalyst, 11.431 g (39.927 mM) of N-(1-benzyl-piperidin-4-yl)trifluoroacetamide was hydrogenated in 100 ml of methanol at room temperature and atmospheric pressure until the starting compound had disappeared (i.e. for 2 hours). The catalyst in the reaction mixture was filtered off with the aid of celite and washed with methanol. The filtrate and washes were pooled and the solvent was distilled off under reduced pressure to provide crude N-(piperidin-4-yl)trifluoroacetamide. This crude product was not purified but used as it was in the next reaction. To a solution of the crude N-(piperidin-4-yl)trifluoroacetamide and 6.68 ml (47.9 mM) of triethylamine in tetrahydrofuran (50 ml)-methanol (20 ml) was added 9.59 g (43.9 mM) of di-tert-butyl dicarbonate dropwise at room temperature and the mixture was stirred at the prevailing temperature overnight. The solvent was then distilled off under reduced pressure and the residue was purified by silica gel column chromatography (hexane/ethyl acetate=3/1) to provide the title compound.

Provenance & Evidence