4-(6-fluoro-3-pyridinyl)-3,6-dihydro-2H-pyridine-1-carboxylic acid tert-butyl ester synthesis

Yield:-

Reaction Conditions:

with dmap;methanesulfonyl chloride in chloroform at 0 - 20;

Steps:

36.2

To a solution of above compound (5.4 g) and 4-dimethylaminopyridine (13.4 g) in chloroform (150 ml), methanesulfonyl chloride (3.53 ml) was added under cooling with ice. After raising the temperature to the ambient level, the system was stirred for an overnight. The reaction liquid was condensed under reduced pressure, ethyl acetate and aqueous citric acid solution were added to the residue, the mixture was stirred and the organic layer was separated. The organic layer was successively washed with water, saturated aqueous solution of sodium hydrogencarbonate and saturated brine. The organic layer was dried over anhydrous sodium sulfate, condensed under reduced pressure, and the resulting residue was purified on column chromatography (hexane/ethyl acetate = 3/1) to provide tert-butyl 4-(6-fluoro-3-pyridinyl)-3,6-dihydro-1(2H)- pyridinecarboxylate (4.70 g).

References:

EP1595867,2005,A1 Location in patent:Page/Page column 33