Butyl bromide → Hydrochloric Acid

Participants

Reaction Steps

To a suspension of (R)-3-[(S)-2-(4-chlorophenyl)isovalerylthio]-2-(2,4-dichlorophenyl)-1-(imidazol-1-yl)-2-propanol (VIb) (49.5 g) obtained in Example 1 in methanol (500 ml) were added a 10% methanolic potassium hydroxide solution (240 g) and n-butylbromide (21.6 g) at -5° to 0° C. in nitrogen atmosphere. The slurry was stirred at the same temperature for 2 hours and then at 30° C. for 3 hours. Methanol was removed by distillation under atmospheric pressure, and the residue was treated with water (200 ml) and extracted with 1,2-dichloroethane (200 ml). The extract was washed successively with water and 12% hydrochloric acid (200 ml) and concentrated in vacuo. To the residue were added toluene (100 ml) and methyl ethyl ketone (35 ml), and the slurry was stirred at 15° C. for 3 hours. Filtration and drying in vacuo gave a crude product (25.7 g), which was recrystallized from methyl ethyl ketone to give (R)-3-(n-butylthio)-2-(2,4-dichlorophenyl)-1-(imidazol-1-yl)-2-propanol (I: n=3) hydrochloride (21.8 g) as colorless needles. Yield, 55%. M.P., 168.5°-170° C. [α]D20 -89.8° (c=1, methanol).

Provenance & Evidence