Hydrochloric Acid → 3-{2-Methyl-3-(1-pyrrolidinyl)propionyl}-2,1-benzisoxazole hydrochloride

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Reaction Steps

Added to 2 ml of dioxane were 2.0 g (11.4 mmol) of the ketone derivative, i.e., 3-propionyl-2,1-benzisoxazole prepared above in the procedure (2), 1.3 g (12.1 mmol) of pyrrolidine hydrochloride, 0.45 g (15.0 mmol) of paraformaldehyde and 2 droplets of 12N-hydrochloric acid. They were reacted under reflux for 30 minutes. After completion of the reaction, water and ethyl ether were added, and a water layer was collected. The water later was alkalinized with an aqueous solution of sodium carbonate and then extracted with ethyl ether. The extract was dried over anhydrous magnesium sulfate. The solvent was then distilled off so that an oily residue was obtained. The oily residue was dissolved in ethyl acetate, followed by the addition of a 4N-hydrochloric acid-dioxane solution under ice cooling. The mixture thus obtained was concentrated at room temperature under reduced pressure. Precipitated crystals of 3-{2-methyl-3-(1-pyrrolidinyl)propionyl}-2,1-benzisoxazole hydrochloride thus formed were collected by filtration, so that the title compound was obtained. Its yield was 0.9 g (30.5%).

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