Hydrogen Bromide → 2-Bromo-5-hydroxy-N-[2-(4-hydroxyphenyl)ethyl]-4-methoxy-N-methylbenzamide

Participants

Reaction Steps

A separate solution of N-methyl-N-(2-[4-hydroxyphenyl]ethyl) amine (A12) was prepared by mixing A12.HBr (100 g), triethylamine (360 mL) in methylene chloride (1000 mL). To this A12 solution was added slowly the above mentioned B13-Cl solution with agitation at room temperature. The reaction mixture was stirred for another one hr at room temperature after the addition was completed. The solid precipitate was removed by filtration and the filter cake was washed with methylene chloride. The combined methylene chloride solution was distilled until the pot temperature reached 55° C. To this residue, methanol (198 g) was added. The methanol of the resulted solution was removed by distillation until the pot temperature reached 70° C. The residue was cooled to room temperature and 15% NaOH/MeOH solution (460 mL) was added. The resulting solution was stirred at room temperature for 12 hr. The reaction mixture was acidified with 36% hydrochloric acid until the pH was between 3 and 5. The solution was set for distillation until the pot temperature reached 75° C. To the residue was added methylene chloride (200 mL) and 1N HCl (1500 mL) and stirred at 0° C. for 4 hr. The precipitate was collect by filtration to give 100 g (56% yield) of N-methyl-N-(2-[4-hydroxyphenyl]ethyl)-2-bromo-5-hydroxy-4-methoxy benzene carboxamide (C2).

Provenance & Evidence