(R)-Tert-butyl 4-benzyl-2-methylpiperazine-1-carboxylate → tert-Butyl (2R)-2-methylpiperazine-1-carboxylate

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Reaction Steps

A mixture of tert-butyl 4-benzyl-(2R)-methyl-1-piperazinecarboxylate (XXII, 5.40 g), ethanol (200 ml) and Pearlman's catalyst (1.36 g) is hydrogenated (36 psi) for 16 hr at 20-25° in a Parr flask. The mixture is filtered and the solids washed successively with ethanol, methylene chloride and methanol. The combined filtrates are concentrated, diluted with methylene chloride, filtered, and concentrated to give the title compound which solidified upon standing, mp 33-36°; [α]25D -59° (CHCl3); IR (mineral oil) 1695, 1408, 1363, 1301, 1226, 1173 and 1095 cm-1 ; NMR (CDCl3) 4.1-4.3, 3.7-3.85, 2.6-3.05, 1.84, 1.46 and 1.22 δ; MS (EI) 200, 144, 127, 99, 70 and 57.

Provenance & Evidence