Hydrochloric Acid → N,N-Dimethyl-2-(1-methylpyrrolidin-3-YL)-2,2-diphenyl-acetamide

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Reaction Steps

To a suspension of 20 g. (0.5 mole) of sodamide in 750 ml. of dry toluene was added dropwise 50.58 g. (0.5 mole) of 1-methyl-3-pyrrolidinol with cooling below 30° C. After stirring for 1 hour, 95.32 g. (0.5 mole) of p-toluene sulfonyl chloride in 500 ml. of dry toluene was added rapidly at a temperature below 10° C. maintained by dry ice/acetone bath. The temperature was allowed to come to room temperature and stirred for 2 hours. The reaction mixture was cooled, washed with 500 ml. of cold water and the toluene layer was dried over calcium sulfate, filtered and the dried toluene solution concentrated at reduced pressure. To 93.5 g. (0.39 mole) of N,N-dimethyl-α,α-diphenylacetamide in 500 ml. of dry toluene was added 15.6 g. (0.4 mole) of sodamide and the mixture was slowly brought to reflux with stirring. After refluxing for 3 hours, the tosylate in 250 ml. of dry toluene was added at a convenient rate to the refluxing reaction mixture which was then refluxed for 3 hours. The resulting suspension was filtered and the toluene filtrate was evaporated under water pump vacuum, leaving an oil which on cooling became semi-crystalline and was taken into 6N hydrochloric acid. The acid solution was extracted with ether, made basic with 6N sodium hydroxide and the base insoluble oil extracted with ether. The ether extracts were dried over calcium sulfate, filtered, and evaporated leaving an amber oil. The product was distilled at 175°-180° C./0.005 mm. to give 22 g. (38%) of product.

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