反应详情

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.

1. temperatureThe solution was cooled with an ice bath
2. customwas slowly added such that T<10° C
3. additionwas then added until pH
4. extractionThe solution was extracted with MTBE (2×)
5. washwashed with water (2×), brine
6. dry with materialdried over Na2SO4
7. filtrationfiltered
8. concentrationconcentrated
9. customto give a brown syrup
10. customfitted with a temperature probe, mechanical stirrer, addition funnel and nitrogen inlet
11. additionHex was then slowly added to the stirring solution over 1 h
12. additionMore Hex was then added over 2 h
13. waitthen left overnight
14. filtrationThe suspension was filtered
15. washwashed with Hex
16. customdried on the fit under nitrogen for 20 h