Benzyl Bromide → 4-Benzyl-1-(tert-butoxycarbonyl)piperidine-4-carboxylic acid

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Reaction Steps

N-tert-butyloxycarbonyl-4-benzylpiperidine-4-carboxylic acid ethyl ester (prepared as in Gilligan et al J. Med. Chem. 1994, 364-370 using benzyl bromide as the alkylating agent) (11.0 g; 32 mmol) was refluxed for 7 h. in a mixture of ethanol (190 ml) and aqueous sodium hydroxide (18% 190 ml). The volume was reduced to a third in vacuo and pH was adjusted to 3 with sodium hydrogen sulfate. Water (300 ml) was added and the mixture was extracted with ethylacetate (2×250 ml). The combined organic phases were evaporated to afford 8.6 g of N-tert-butyloxycarbonyl-4-benzylpiperidine-4-carboxylic acid.

Provenance & Evidence