反应详情

A mixture of 2,5-dichlorobenzoic acid (9.5 g.), 2-methoxyphenol (7.4 g.) and copper bronze (1.0 g.) is added to a solution of sodium methoxide in methanol prepared from sodium (2.53 g.) and methanol (50 ml.). The excess methanol is evaporated and 1,2-dichlorobenzene (50 ml.) is added to the residue. The mixture is stirred and heated under reflux for 2.5 hours. The mixture is cooled, acidified with 3 N hydrochloric acid, filtered to remove copper bronze and extracted with chloroform. The organic layer is separated and extracted with saturated sodium hydrogen carbonate solution. The sodium hydrogen carbonate extract is acidified. The precipitate is filtered off, dissolved in toluene, and the toluene solution treated with carbon, filtered and the solvent evaporated. The solid residue is recrystallised from toluene-petroleum ether (b.p. 60°-80° C.) to give 5-chloro-2-(2'-methoxyphenoxy)benzoic acid, m.p. 115°-118° C.

1. customThe excess methanol is evaporated
2. addition1,2-dichlorobenzene (50 ml.) is added to the residue
3. temperatureheated
4. temperatureunder reflux for 2.5 hours
5. temperatureThe mixture is cooled
6. filtrationfiltered
7. customto remove copper bronze
8. extractionextracted with chloroform
9. customThe organic layer is separated
10. extractionextracted with saturated sodium hydrogen carbonate solution
11. extractionThe sodium hydrogen carbonate extract
12. filtrationThe precipitate is filtered off
13. dissolutiondissolved in toluene
14. additionthe toluene solution treated with carbon
15. filtrationfiltered
16. customthe solvent evaporated
17. customThe solid residue is recrystallised from toluene-petroleum ether (b.p. 60°-80° C.)