反应详情

N,N-dimethyl-5-methyl-2-(2′,4′-dichloro-6′-methylanilino)phenylacetamide (1.5 g, 4.3 mmol) is hydrolyzed with 6N NaOH (70 ml) as a two phase solution with n-BuOH (40 ml) at reflux temperature for 14 hours. After cooling to room temperature, the mixture is poured over ice (100 ml). Toluene (100 ml) is added and the mixture transferred to a separatory funnel. The aqueous phase is brought to a pH of 1 with 3 N HCl. The organic phase is separated and the aqueous phase re-extracted with toluene (100 ml). The combined organic solution is dried (MgSO4) and concentrated under high vacuum (35–50 mbar), on a rotovap, taking care not to warm above 50°. Upon crystallization from Et2O/hexane, 5-methyl-2-(2′,4′-dichloro-6′-methylanilino)phenylacetic acid is obtained as a tan solid, m.p. 137–141°.

1. temperatureat reflux temperature for 14 hours
2. customthe mixture transferred to a separatory funnel
3. customThe organic phase is separated
4. extractionthe aqueous phase re-extracted with toluene (100 ml)
5. dry with materialThe combined organic solution is dried (MgSO4)
6. concentrationconcentrated under high vacuum (35–50 mbar), on a rotovap
7. temperatureto warm above 50°
8. customUpon crystallization from Et2O/hexane