Trifluoromethanesulfonic acid → (R)-9-[4-hydroxy-2-(stearoyloxymethyl)butyl]guanine

Participants

Reaction Conditions

Reaction Steps

The product of Example 30, step d) (3.0 kg) was slurried in THF (46 L) at 20° C. A solution of trifluoromethanesulfonic acid (2.25 kg) in 2.25 kg of water (prepared by slowly adding the acid to cold water) was added and the reaction mixture was stirred at 22° C. for 2 hours. The reaction mixture was cooled to 15° C. and quenched with a solution of NaHCO3 (1.5 kg) in water (5.3 kg). Borane t-butylamine complex (powder, 340 g) was added in four portions and then the reaction temperature was increased to 35° C. and stirred for 12 hours. The reaction mixture was added to a solution of 320 g of concentrated HCl (37% aq.) in 115 kg of tap water at 5° C. This mixture was stirred for 30 minutes and the resulting precipitate was filtered and washed with acetonitrile (15 kg). The solids were reprecipitated once or twice from acetone (35 kg). A final precipitation was accomplished by dissolving the product in THF (24 kg) at 65° C., adding water (1.3 kg), cooling to 30° C. and then adding methylene chloride (105 kg). The resulting slurry was cooled to 10° C. and the precipitate was filtered to provide the desired product.

Provenance & Evidence