反应详情

13.72 g (106.72 mmol) 3-chlorophenol were added to a mixture of 19.21 g (106.72 mmol) sodium methylate-solution (30% in methanol) and 200 ml toluene and the mixture stirred 15 minutes at room temperature. The solution was evaporated to dryness, the residue suspended in 100 ml of toluene and evaporated to dryness again. The residue was dissolved in 100 ml dimethylsulphoxide and 24 g (101.65 mmol) of ethyl-2-bromothiazole-4-carboxylate [prepared as in Example 1b] were added in one portion. The solution was stirred for 24 hours at 80° C., cooled to room temperature and poured into 1200 ml water. 200 ml of saturated sodium chloride solution were added and the mixture extracted three times with 300 ml toluene. The organic layers were combined and washed with 200 ml 0.1 m NaOH and 200 ml of diluted sodium chloride solution, dried over Na2SO4 and evaporated to dryness to give 27.72 g (96%) of pale brown oily ethyl-2-(3-chlorophenoxy)thiazole-4-carboxylate. NMR (CDCl3):1.35(t,3H,CH3); 4.4(q,2H,CH2); 7.3(m,4H,Arom.) 7.7(s,1H,arom.).

1. customThe solution was evaporated to dryness
2. customevaporated to dryness again
3. dissolutionThe residue was dissolved in 100 ml dimethylsulphoxide
4. stirringThe solution was stirred for 24 hours at 80° C.
5. temperaturecooled to room temperature
6. extractionthe mixture extracted three times with 300 ml toluene
7. washwashed with 200 ml 0.1 m NaOH and 200 ml of diluted sodium chloride solution
8. dry with materialdried over Na2SO4
9. customevaporated to dryness