Indole-3-Acetic Acid → Methyl indole-3-acetate

Beteiligte Stoffe

Reaktionsschritte

Concentrated sulfuric acid (0.2 equiv.) was carefully added to a solution of 1H-indol-3-ylacetic acid in MeOH (1 M) and the reaction was stirred at rt for 2.5 h. The solution was cooled with an ice bath, and aqueous 2 N NaOH (0.18 equiv.) was slowly added such that T<10° C. The solution was diluted with water, and solid K2CO3 was then added until pH was neutral. The solution was extracted with MTBE (2×), washed with water (2×), brine, dried over Na2SO4, filtered, and concentrated to give a brown syrup. The crude syrup was dissolved in MTBE (1.4 mL/g) and transferred to a three necked flask fitted with a temperature probe, mechanical stirrer, addition funnel and nitrogen inlet. Hex was then slowly added to the stirring solution over 1 h. More Hex was then added over 2 h then left overnight. The suspension was filtered, washed with Hex, and dried on the fit under nitrogen for 20 h to give the title compound (81%) as a light orange solid.

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