Hydrochloric Acid → Naratriptan

Participants

Reaction Steps

A solution of the product of stage (i) (5.78 g) in a mixture of ethanolic hydrogen chloride [prepared by adding acetyl chloride (1.71 g, 21.8 mmol) to IMS ethanol (400 ml) with stirring] and dimethylformamide (300 ml; added to the above to dissolve the starting material) was hydrogenated at room temperature and atmospheric pressure, using 10% palladium on carbon (5.00 g, 50% w/w with water) as the catalyst until uptake of hydrogen ceased. The mixture was filtered and the filtrate was evaporated to give a solid. The solid was partitioned between 2N sodium carbonate (60 ml) and ethyl acetate (200 ml) and the mixture was heated until the solid had dissolved. The phases were separated, the aqueous phase was extracted with ethyl acetate (200 ml) and the combined organic phases were washed with saturated brine (100 ml), dried (Na2SO4) and evaporated to give a gum. The gum was crystallised from ethyl acetate (60 ml) to give the title compound (4.30 g) as crystals, with m.p. 170°-171°

Provenance & Evidence