Tetrabutylammonium Fluoride → 6-(4-Ethynyl-2-methyl-phenylamino)-7-fluoro-3H-benzoimidazole-5-carboxylic acid cyclopropylmethoxy-amide

Participants

Reaction Conditions

Reaction Steps

7-Fluoro-6-(2-methyl-4-trimethylsilanylethynyl-phenylamino)-3H-benzoimidazole-5-carboxylic acid cyclopropylmethoxy-amide 11bbb (0.020 g, 0.044 mmol) is dissolved in tetrahydrofuran (0.50 mL) and the reaction solution is cooled to 0° C. TBAF (50 uL, 0.050 mmol, 1 M solution in tetrahydrofuran) is added. The reaction mixture is warmed to room temperature and additional TBAF (25 uL, 0.025 mmol, 1 M solution in tetrahydrofuran) is added. The reaction mixture is stirred at 50° C. for 2 hours under N2. The reaction mixture is cooled to room temperature, a few drops of H2O are added and then it is concentrated under reduced pressure. The residue is purified by FCC (eluting with 20:1 methylene chloride:methanol) to yield 0.011 g (65%) of the pure desired product. MS APCI (−) m/z 377 (M−1) detected; 1H NMR (400 MHz, CDCl3) δ 10.56 (broad s, 1H), 8.12 (s, 1H), 7.99 (s, 1H), 7.28 (s, 1H), 7.11 (d, 1H), 6.42 (broad, 1H), 3.70 (br s, 2H), 2.96 (d, 1H), 2.37 (s, 3H), 0.85 (m, 1H), 0.50 (m, 2H), 0.22 (m, 2H).

Provenance & Evidence