반응 #530645

반응 방정식

4-Trifluoromethylaniline

(R)-2-bromo-3-methylbutanoic acid

potassium hydroxide

phenolphthalein

→

(R)-2-(4-trifluoromethylphenylamino)-3-methylbutanoic acid

용매

methanol

methanol

반응 조건

후처리

1. 1
   기타The methanol is then removed under high vacuum at 35°
2. 2
   온도the mixture is heated in a pre-heated oil bath (90°) under nitrogen for 30 minutes
3. 3
   온도The mixture is then cooled
4. 4
   기타by partitioning between pentane/5% sodium hydroxide
5. 5
   기타The layers are separated
6. 6
   추출the pentane phase is extracted with 5% sodium hydroxide (2×)
7. 7
   추출The combined aqueous phases are extracted with pentane (2×)
8. 8
   추출The aqueous phase is then extracted with ether (3×)
9. 9
   세척the combined ether phases are washed with brine
10. 10
    건조dried over magnesium sulfate
11. 11
    여과Filtration and evaporation

실험 절차

A solution of 10.01 g (55.3 mmol) of (R)-2-bromo-3-methylbutanoic acid in methanol is titrated with 1 M potassium hydroxide (~53 ml) in methanol to the phenolphthalein endpoint. The methanol is then removed under high vacuum at 35°, and the solid is kept at 35° under high vacuum for one hour. 4-Trifluoromethylaniline (23.89 g, 148.3 mmol) is added to the salt, and the mixture is heated in a pre-heated oil bath (90°) under nitrogen for 30 minutes. The mixture is then cooled and worked up immediately by partitioning between pentane/5% sodium hydroxide. The layers are separated and the pentane phase is extracted with 5% sodium hydroxide (2×). The combined aqueous phases are extracted with pentane (2×) and acidified with cold conc. hydrochloric acid. The aqueous phase is then extracted with ether (3×), and the combined ether phases are washed with brine and dried over magnesium sulfate. Filtration and evaporation yield (R)-2-(4-trifluoromethylphenylamino)-3-methylbutanoic acid.

출처