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906329-50-8

N-BOC-4-(4'-FLUORO) BENZYL-4-PIPERIDINE CARBOXYLIC ACID synthesis

2synthesis methods
-

Yield:-

Reaction Conditions:

Stage #1: 1-tert-butyl 4-methyl 4-(4-fluorobenzyl)piperidine-1,4-dicarboxylatewith methanol;lithium hydroxide;water in tetrahydrofuran at 65; for 1 h;
Stage #2: with sodium hydroxide in diethyl ether;
Stage #3: with hydrogenchloride in diethyl ether; pH=1;

Steps:

13.1

A solution of lithium hydroxide monohydrate (11.2 g, 267 mmol) in water (50 mL) was added to a solution of l-tert-butyl 4-methyl 4-(4-fluoro-phenylmethyl)-piperidine-l,4- dicarboxylate (9.37 g, 26.7 mmol), prepared using procedures similar to those in Reference 12, in THF/MeOH (200 mL, 1 :1 v/v). The mixture then was heated to 65 °C for 1 day. The mixture was allowed to cool to room temperature and a solution of sodium hydroxide (I M, 100 mL) and ether (300 mL) was added. The aqueous phase was separated and acidified with cone, hydrochloric acid (~35 mL) to pH 1. The aqueous phase was extracted with ethyl acetate (200 mL, 100 mL) and the organic layer was dried over Na2SO4, filtered and concentrated under reduced pressure. The ethereal layer was acidified with cone, hydrochloric acid and the aqueous phase separated. The ethereal layer then was dried over Na2SO4, filtered to give l-tert-butoxycarbonyl-4-(4-fluoro-phenylmethyl)-piperidine-4- EPO carboxylic acid as a white powder (8.16 g). 1H NMR (400 MHz, d6-DMSO) δ 1.29-1.39 (m, 2H), 1.37 (s, 9H), 1.84 (brd, 2H5 J= 13.2 Hz)5 2.78 (brs, 4H), 3.77 (brd, 2H, J= 13.2 Hz)5 7.06-7.16 (m, 4H)5 12.58 (brs, IH). MS(ES) m/z 336.4 (M-I)-; MS cald: 337.2 (M).

References:

WO2006/86609,2006,A2 Location in patent:Page/Page column 161-162

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