Hydrochloric Acid → HCID 86759286, compound

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Reaction Steps

After adding portionwise 140 ml of concentrated sulfuric acid to 160 ml of water under stirring and cooling, 40 ml of concentrated hydrochloric acid, 88 g (0,2 mol) of 1-benzyl-4-(4-fluorophenyl)-1,2,5,6-tetrahyropyridine tosylate and 8 g (0.267 mol) of paraformaldehyde are added at room temperature. The mixture is stirred at 80° C. for one hour, 300 ml of toluene and then 300 ml of water are added. Finally, the mixture is alkalinized by adding a solution of 240 g of sodium hydroxide in 500 ml of water at a temperature not higher than 40° C. under cooling. After separating the mixture at 30° C., the aqueous layer is extracted with 50 ml of toluene. The combined toluene solution is extracted successively with 3.2 ml of concentrated hydrochloric acid diluted with 200 ml of water, and then with the solution of 1 ml of concentrated hydrochloric acid in 100 ml of water. After drying, the organic phase over anhydrous magnesium sulfate and filtering, the filtrate is evaporated to dryness under reduced pressure. The evaporation residue is a light yellow thick oil, which is dissolved in 100 ml of acetone and 30 g of p-toluenesulfonic acid monohydrate are added. The crystalline precipitate is stirred at 10° C. for one hour, then filtered, twice washed with 10 ml of acetone each, and dried to yield 56 g (59.7%) of the title compound, m.p.: 170-172° C.

Provenance & Evidence