反应详情

A solution of 10 g of Lithium 3-ethoxycarbonyl-2-methyl-3-oxo-1-(4-trifluoromethyl-phenyl)-propan-1-olate, 6.9 g of (2,4-Dichloro-phenyl)-hydrazine hydrochloride and 74 ml of sulfuric acid (50%) in 184 ml of ethanol was heated to reflux for 7 h. After cooling to room temperature the organic solvents were removed under reduced pressure and the residue was diluted with 100 ml of water and extracted with ethyl acetate. The combined organic layers were dried over MgSO4 and the solvent was removed under reduced pressure. The residue was dissolved in 100 ml THF and a solution of 1.4 g of LiOH in 20 ml water was added at room temperature. The reaction mixture was heated to 60° C. for 7 h. Then, after cooling to room temperature the mixture was acidified to pH 1 by addition of half-concentrated hydrochloric acid. The precipitating product was collected by filtration and washed with water. The residue was codistilled twice with dichloromethane and twice with toluene. The isolated crude product was used in the next reaction step. Yield: 13 g.

1. temperatureto reflux for 7 h
2. customwere removed under reduced pressure
3. additionthe residue was diluted with 100 ml of water
4. extractionextracted with ethyl acetate
5. dry with materialThe combined organic layers were dried over MgSO4
6. customthe solvent was removed under reduced pressure
7. dissolutionThe residue was dissolved in 100 ml THF
8. additiona solution of 1.4 g of LiOH in 20 ml water was added at room temperature
9. temperatureThe reaction mixture was heated to 60° C. for 7 h
10. temperatureThen, after cooling to room temperature the mixture
11. additionwas acidified to pH 1 by addition of half-concentrated hydrochloric acid
12. filtrationThe precipitating product was collected by filtration
13. washwashed with water
14. customThe isolated crude product
15. customwas used in the next reaction step