反应详情

A mixture of methyl 4-[5-(4-trifluoromethylphenyl)-1,3,4-thiadiazol-2-yl]benzoate (0.838 g), 1 M aqueous sodium hydroxide solution (5 ml), tetrahydrofuran (100 ml) and methanol (50 ml) was heated under reflux for 1 hr. After cooling, the reaction mixture was poured into water, and 1 M hydrochloric acid was added to acidify the mixture. The mixture was extracted with ethyl acetate-tetrahydrofuran (1:1, volume ratio). The organic layer was washed with water and saturated brine, dried over anhydrous magnesium sulfate and concentrated. The residue was recrystallized from tetrahydrofuran to give 4 [5-(4-trifluoromethylphenyl)-1,3,4-thiadiazol-2-yl]benzoic acid (0.672 g, yield 83%) as a colorless crystalline powder. melting point: >300° C.

1. temperaturewas heated
2. temperatureunder reflux for 1 hr
3. temperatureAfter cooling
4. additionwas added
5. extractionThe mixture was extracted with ethyl acetate-tetrahydrofuran (1:1, volume ratio)
6. washThe organic layer was washed with water and saturated brine
7. dry with materialdried over anhydrous magnesium sulfate
8. concentrationconcentrated
9. customThe residue was recrystallized from tetrahydrofuran