3-Amino-2-(4-chloro-phenylethynyl)-benzoic acid methyl ester → 2-(4-Chloro-phenyl)-1H-indole-4-carboxylic acid methyl ester

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Reaction Steps

3-amino-2-(4-chloro-phenylethynyl)-benzoic acid methyl ester (0.73 g, 2.54 mmol) and palladium (II) chloride (23 mg, 0.13 mmol) were combined in 10 mL acetonitrile. The yellow solution was stirreed under argon at 75° C. for 17 h. The solvent was removed in vacuo leaving an orange solid which was purified by flash chromatography eluting with 50 to 100% CH—Cl3/hecanes. 2-(4-chloro-henyl)-1H-indole-4-carboxylic acid methyl ester; 0.53 g (72%) was isolated as an off-white solid: m.p. 150.0-151.5° C.; 1H NMR (300 MHz, d6-DMSO) δ 3.93 (s, 3H), 7.23 (app t, J=7.8 Hz, 1H), 7.41 (d, J=1.8 Hz, 1H), 7.57 (d, J=8.7 Hz, 2H), 7.68 (d, J=7.8 Hz, 1H), 7.75 (dd, J=7.5, 0.9 Hz, 1H), 7.95 (d, J=8.7 Hz, 2H), 11.99 (br s, 1H). HRMS (MALDI, MH+) Calcd for C16H12ClNO2: 286.0635. Found: 286.0631.

Provenance & Evidence