Triethylamine → 2-(3,4-Difluorobenzyl)-1-(methoxycarbonyl)piperidine-4-carboxylic acid

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Reaction Steps

Dimethyl 2-(3,4-difluorobenzyl)piperidine-1,4-dicarboxylate (7.010 g, 21.42 mmol) was dissolved in acetonitrile (75 mL) and water (1.5 mL). Lithium bromide (14.88 g, 171.33 mmol) and triethylamine (11.87 mL, 85.66 mmol) were added and the resulting yellow suspension was heated at reflux for 3 h. Water (100 mL) and MTBE (300 mL) were added. The organic phase was extracted with water (×2). The pooled aqueous layer was acidified to pH 1 with 3.8 M HCl and then extracted with MTBE (×2). The combined organic layer was washed with water, dried over Na2SO4, filtered and evaporated to yield 2-(3,4-difluorobenzyl)-1-(methoxycarbonyl)piperidine-4-carboxylic acid (6.62 g, 99%) as a yellow solid. MS m/z 314 (M+H)+

Provenance & Evidence