Hydrochloric Acid → Naratriptan

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°

1. additionadded to the above
2. dissolutionto dissolve the starting material)
3. customwas hydrogenated at room temperature
4. filtrationThe mixture was filtered
5. customthe filtrate was evaporated
6. customto give a solid
7. customThe solid was partitioned between 2N sodium carbonate (60 ml) and ethyl acetate (200 ml)
8. temperaturethe mixture was heated until the solid
9. dissolutionhad dissolved
10. customThe phases were separated
11. extractionthe aqueous phase was extracted with ethyl acetate (200 ml)
12. washthe combined organic phases were washed with saturated brine (100 ml)
13. dry with materialdried (Na2SO4)
14. customevaporated
15. customto give a gum
16. customThe gum was crystallised from ethyl acetate (60 ml)

ORD record

ord-8925c0785b304810ac7fb4438c5f63c9

Source dataset

uspto-grants-1991_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04997841