反应详情

2-Methyl-4-p-tolyl-thiazole-5-carboxylic acid methyl ester (2.67 mmol) and solid KOH (5.35 mmol) were dissolved in ethanol (1.04 mL) and water (0.26 mL) and heated under reflux for 3 hours. After cooling, the solvent was evaporated under reduced pressure and ice water was added to the residue, followed by washing with hexane. The aqueous layer was acidified with 1N aq. HCl and the crystals thus precipitated were collected by filtration, washed with water and then dried to provide 2-methyl-4-p-tolyl-thiazole-5-carboxylic acid. LC-MS: tR=0.83 min; [m+H]+=234.02.

1. temperatureunder reflux for 3 hours
2. temperatureAfter cooling
3. customthe solvent was evaporated under reduced pressure and ice water
4. additionwas added to the residue
5. washby washing with hexane
6. customthe crystals thus precipitated
7. filtrationwere collected by filtration
8. washwashed with water
9. customdried