反应详情

温度

-78 °C

n-Butyllithium (2.5M in hexane, 100 ml) was added to a cooled solution of 2-chloro-6-fluorotoluene (36.1 g) in dry tetrahydrofuran while maintaining the temperature below -60° C. The mixture was stirred at -78° C. overnight then poured onto solid carbon dioxide pellets. The mixture was stirred and allowed to warm to room temperature. It was acidified to pH 1 and extracted with ether. The organic layer was extracted into aqueous sodium hydroxide solution (2M) and water. The combined aqueous extracts were acidified to pH 1 and the solid formed was filtered off and washed with water and n-hexane to give 4-chloro-2-fluoro-3-methylbenzoic acid (40.35 g) as a white solid, NMR (DMSO-d6) 2.3(d,3H), 7.4(d,1H) 7.7(t,1H).

1. temperaturewhile maintaining the temperature below -60° C
2. stirringThe mixture was stirred
3. temperatureto warm to room temperature
4. extractionextracted with ether
5. extractionThe organic layer was extracted into aqueous sodium hydroxide solution (2M) and water
6. customthe solid formed
7. filtrationwas filtered off
8. washwashed with water and n-hexane