Isovaleryl chloride → HCID 68719603, compound

Participants

Reaction Conditions

Reaction Steps

Preparation of 5-(3-Methyl-butyryl)-1H-indole-2-carboxylic acid (Froshauer, S. A.; Goldstein, S. W.; Stirtan, W. G. U.S. Pat. No. 5,981,762): 3-Bromo-1H-indole-2-carboxylic acid ethyl ester (536 mg, 2.0 mmol), prepared as previously described (Elliott, J. D.; Leber, J. D.; Thompson, S. K.; Halbert, S. M. U.S. Pat. No. 5,684,032) was dissolved in nitromethane (10 mL) and cooled to 0° C. AlCl3 was added to the flask. Then a solution of isovaleryl chloride (0.295 mL, 2.4 mmol) in nitromethane (2 mL) was added dropwise to the flask. The mixture was allowed to come to room temperature and stirred for 18 hours. The mixture was then cooled to 0° C. 20 mL ice-water was added and extracted with CH2Cl2 (4×20 mL). The combined organic phase was washed with saturated brine (20 mL), 1N NaHCO3 (20 mL) and saturated brine (2×20 mL), Dried over anhydrous Na2SO4, filtered, and concentrated under vacuum to give yellow solid. It was then purified by flash column chromatography eluted with hexane:ethyl acetate (6:1) to give 3-Bromo-5-(3-methyl-butyryl)-1H-indole-2-carboxylic acid ethyl ester (468 mg, 67%) as light yellow solid.

Provenance & Evidence