反应详情

A sample of the diethyl (2,5-dimethylphenyl)-hydroxymalonate (21 parts) was reacted with a solution of potassium hydroxide (21 parts) in water (84 parts) at 98° C. for 5 hours. After cooling to ambient temperature, the reaction was washed with diethyl ether and acidified with 10M hydrochloric acid. After heating to 98° C. for a further 2 hours, the cooled materials was extracted into diethyl ether. The separated organic phase was dried over magnesium sulfate, filtered and the solvent was evaporated under reduced pressure. The crude amber coloured oil (15 parts) solidified on standing. Recrystallisation from toluene gave 2,5-dimethylmandelic acid (7 parts). The 1Hnmr, 13Cnmr and mass spectra were all consistent with the structure.

1. washthe reaction was washed with diethyl ether
2. temperatureAfter heating to 98° C. for a further 2 hours
3. extractionthe cooled materials was extracted into diethyl ether
4. dry with materialThe separated organic phase was dried over magnesium sulfate
5. filtrationfiltered
6. customthe solvent was evaporated under reduced pressure
7. customRecrystallisation from toluene