6-(4-Bromo-2-methyl-phenylamino)-7-fluoro-3-pent-4-enyl-3H-benzoimidazole-5-carboxylic acid methyl ester → 6-(4-Bromo-2-methyl-phenylamino)-7-fluoro-3-pent-4-enyl-3H-benzoimidazole-5-carboxylic acid

Participants

Reaction Steps

6-(4-Bromo-2-methyl-phenylamino)-7-fluoro-3-pent-4-enyl-3H-benzoimidazole-5-carboxylic acid methyl ester 9b is dissolved in 1:1 THF/MeOH (10 mL) and 1 N NaOH solution (2.3 mL) is added. After 5 hours, the organic solvents are removed under reduced pressure and the residue diluted with water and 100 mL 1:1 THF:ethyl acetate. The layers are separated and the aqueous layer extracted with ethyl acetate. The combined organic extracts are dried (Na2SO4) and concentrated under reduced pressure to afford 0.39 g (100%) clean desired product as a light yellow solid.

Provenance & Evidence