反应详情

温度

70 °C

200 mg of Ethyl 2-(4-hydroxy-3-nitrophenyl)-4-methyl-5-thiazolecarboxylate prepared in (1) was dissolved in 3 ml of N,N-dimethylformamide, 540 mg of anhydrous potassium carbonate and 440 mg of isopropyl bromide were added thereto, and the mixture was heated at 70° C. for 18 hours. After the reaction mixture was cooled, 20 ml of water was added thereto. The mixture was extracted twice with 30 ml of ethyl acetate. The organic layer was washed with a saturated aqueous sodium chloride solution, and the solvent was removed by distillation. The resulting crystal was recrystallized from ethanol to give 172 mg of ethyl 2-(4-isopropoxy-3-nitrophenyl)-4-methyl-5-thiazolecarboxylate. This product was hydrolyzed by a conventional process, and the resulting crystal was recrystallized from a 80% aqueous ethanol solution to give 135 mg of 2-(4-isopropoxy-3-nitrophenyl)-4-methyl-5-thiazolecarboxylic acid (yield:

1. temperatureAfter the reaction mixture was cooled
2. extractionThe mixture was extracted twice with 30 ml of ethyl acetate
3. washThe organic layer was washed with a saturated aqueous sodium chloride solution
4. customthe solvent was removed by distillation
5. customThe resulting crystal was recrystallized from ethanol