反应详情

温度

70 °C

730 mg of 3-Nitrothiobenzamide was dissolved in 5 ml of ethanol, 725 mg of ethyl 2-chloroacetoacetate was added to the solution, and the mixture was heated under reflux for 18 hours. After the reaction mixture was cooled, the precipitated crystal was collected by filtration and recrystallized from a mixed solvent consisting of 10 ml of ethanol and 5 ml of ethyl acetate. 800 mg out of 898 mg of the resulting crystal was suspended in 10 ml of ethanol, 10 ml of an aqueous 1N sodium hydroxide solution was added to the suspension, and the mixture was heated at 70° C. for 2 hours. After the completion of the reaction, ethanol was removed by distillation, and the residue was neutralized with 1N hydrochloric acid. The precipitated crystal was collected by filtration and recrystallized from an aqueous 50% ethanol solution to give 560 mg of 4-methyl-2-(3-nitrophenyl)-5-thiazolecarboxylic acid (yield: 59%).

1. temperaturethe mixture was heated
2. temperatureunder reflux for 18 hours
3. temperatureAfter the reaction mixture was cooled
4. filtrationthe precipitated crystal was collected by filtration
5. customrecrystallized from a mixed solvent
6. addition10 ml of an aqueous 1N sodium hydroxide solution was added to the suspension
7. customAfter the completion of the reaction, ethanol
8. customwas removed by distillation
9. filtrationThe precipitated crystal was collected by filtration
10. customrecrystallized from an aqueous 50% ethanol solution