4-Toluenesulfonyl chloride → 1-Methylpiperidin-4-yl 4-methylbenzenesulfonate

Participants

Reaction Conditions

Reaction Steps

1-Methyl-4-piperidyl para-toluenesulphonate may be obtained in the following manner: para-toluenesulphonyl chloride (19.60 g) is added in the course of approximately 1 hour 30 minutes to a solution, cooled to 0° C., of 4-hydroxy-1-methylpiperidine (11.50 g) in pyridine (50 cc), and the mixture is stirred for 4 hours at 0° C. and then 12 hours at a temperature in the region of 20° C. After the addition of triethylamine (14.10 g) and stirring for a further 15 minutes, distilled water (300 cc) and ethyl acetate (300 cc) are added. The aqueous phase is separated after settling has taken place and washed with ethyl acetate (200 cc). The organic extracts are combined, washed with distilled water (500 cc in total), dried over anhydrous magnesium sulphate and evaporated to dryness under reduced pressure (20 mm Hg; 2.7 kPa) at a temperature in the region of 45° C. The final traces of pyridine are removed under a higher vacuum (0.1 mm Hg; 13.5 Pa). 1-Methyl-4-piperidyl para-toluenesulphonate (19.6 g) is thereby obtained in the form of a brown oil [Rf=0.56; thin-layer chromatography on silica; eluent: acetonitrile/ammonia solution (d=0.92) (95:5 by volume)].

Provenance & Evidence