反应详情

A mixture of 8.0 g of magnesium turnings, 33 g of anhydrous ethanol and 3 ml of carbon tetrachloride was allowed to react on standing for several minutes. After the exothermic reaction had subsided, 250 ml of anhydrous toluene was slowly added under stirring, and the reaction mixture was stirred at 30°-35° C for an additional 3 hours. To the resulting suspension of magnesium ethoxide, a solution of 84.6 g of α-acetyl-γ-butyrolactone in 100 ml of anhydrous toluene was added dropwise under cooling at 0°-5° C. After the resulting mixture was stirred at room temperature for one hour, crude 4-fluoro-2-nitrobenzoyl chloride, prepared from 55.5 g of 4-fluoro-2-nitrobenzoic acid and 170 ml of thionyl chloride, in 100 ml of anhydrous toluene was added dropwise at 20°-25° C and stirred for an additional 3 hours. After 700 ml of 5% sulfuric acid was added to the resulting mixture under cooling with an ice-salt bath, the organic layer was separated, and the aqueous layer was extracted with portions of toluene. The resulting organic layer contained α-acetyl-α-(4-fluoro-2-nitrobenzoyl)-γ-butyrolactone as the main product. The combined organic layer was washed with water and aqueous saturated sodium chloride solution and extracted with three portions of cold 5% aqueous ammonium hydroxide solution. The combined aqueous ammonium hydroxide layer was washed with toluene and acidified by slow addition of 25% sulfuric acid under cooling. The precipitated solid was collected by filtration, washed with water and dried to give 63.5 g (83.6%) of α-(4-fluoro-2-nitrobenzoyl)-γ-butyrolactone. M.P. 87°-89° C.

1. customto react
2. waiton standing for several minutes
3. customAfter the exothermic reaction
4. stirringthe reaction mixture was stirred at 30°-35° C for an additional 3 hours
5. temperatureunder cooling at 0°-5° C
6. stirringAfter the resulting mixture was stirred at room temperature for one hour
7. additionwas added dropwise at 20°-25° C
8. stirringstirred for an additional 3 hours
9. temperatureunder cooling with an ice-salt bath
10. customthe organic layer was separated
11. extractionthe aqueous layer was extracted with portions of toluene
12. washThe combined organic layer was washed with water and aqueous saturated sodium chloride solution
13. extractionextracted with three portions of cold 5% aqueous ammonium hydroxide solution
14. washThe combined aqueous ammonium hydroxide layer was washed with toluene
15. additionacidified by slow addition of 25% sulfuric acid
16. temperatureunder cooling
17. filtrationThe precipitated solid was collected by filtration
18. washwashed with water
19. customdried