反应详情

温度

220 °C

To a 500 ml. flask were added 200 grams of pyridine hydrochloride. The flask was fitted with a magnetic stirrer, a reflux condenser, and a nitrogen bubbler. The pyridine salt was heated to about 180° C. to remove any moisture. The salt then was allowed to cool somewhat, and 34 grams (0.243 mole) of the fluorotoluene compound were added. The mixture was heated to 220° C. and maintained there for about 3 hours. The mixture then was cooled, and a large volume of water was added. The reaction mixture then was extracted with several portions of methylene chloride. The methylene chloride extracts were combined, and the solvent was removed in vacuo to obtain a pale yellow product which by nmr analysis indicated the presence of about 5 percent of starting material. The product then was taken up in an excess of 1M sodium hydroxide. The solution was extracted with methylene chloride, and the aqueous layer then was acidified with hydrochloric acid. The acidified portion was extracted with methylene chloride. Evaporation of the methylene chloride extract and distillation of the residue gave 26.6 grams of 2-fluoro-5-methylphenol, b.p.30 86°-93° C.

1. customThe flask was fitted with a magnetic stirrer, a reflux condenser
2. customto remove any moisture
3. temperatureto cool somewhat
4. temperaturemaintained there for about 3 hours
5. temperatureThe mixture then was cooled
6. extractionThe reaction mixture then was extracted with several portions of methylene chloride
7. customthe solvent was removed in vacuo
8. customto obtain a pale yellow product which by nmr analysis
9. extractionThe solution was extracted with methylene chloride
10. extractionThe acidified portion was extracted with methylene chloride
11. customEvaporation of the methylene chloride
12. extractionextract
13. distillationdistillation of the residue