Hydrochloric Acid → Taprizosin

Participants

Reaction Steps

To a stirred solution of 6-amino-3,4-dimethoxy-2-(2-pyridyl)benzonitrile (see Example 2 or 2A, 7 g, 27 mmol) and N-(2-cyano-1,2,3,4-tetrahydro-5-isoquinolyl)methanesulfonamide (see Example 3 or 3A, 9 g, 36 mmol) in DMSO (21 ml) at room temperature, was added sodium-t-pentoxide (9.5 g, 92 mmol) portionwise over 20 minutes keeping the temperature below 30° C. The resulting slurry was then stirred for 2 hours. After this time, iced water (35 ml) was added over 1 minute followed by ethyl acetate (35 ml) before reducing the pH of the biphasic mixture to 8.0 with 2M aqueous HCl (20 ml). The aqueous phase was extracted with ethyl acetate (50 ml). The combined organics were washed with saturated NaCl solution (2×30 ml), reduced in volume and stirred for 3 hours. After this time, the resulting slurry was filtered to yield 10.2 g (74%) of the title compound.

Provenance & Evidence