反应详情

To 300 ml of dried dimethylformamide, was added 5.6 g (0.05 mol.) of potassium tert-butoxide and 8.9 g (0.05 mol.) of 1-phenyl-5-mercaptotetrazole. The mixture was stirred for 20 minutes at room temperature. Thereafter, to the mixture which was cooled to 5° C. and kept there, was added gradually dropwise a solution prepared by adding 13 g (0.04 mol.) of 3-chloro-3-(2,4-dichlorophenyl)phthalide in 75 ml of dried dimethylformamide. After dropwise addition, the cooling bath was removed, and the mixture was stirred for 5 hours at room temperature. Thereto, 300 ml of a saturated aqueous solution of ammonium chloride was added. The reaction mixture was extracted with ethyl acetate repeatedly. The extract was washed with water, and the resulting organic layer was dried over anhydrous sodium sulfate. Sodium sulfate was filtered off with suction, and the filtrate was concentrated to yield 23.5 g of oily substance. This oily substance was separated and purified by flash column chromatography (silica gel: 800 g, eluate: hexane-ethyl acetate (3:1 by volume) mixture). Thus, the intended compound, 3-(1-phenyl-tetrazole-5-ylthio)-3-(2,4-dichlorophenyl)phthalide (3), was obtained in a form of white crystals. Yield 7.8 g, Melting Point 148° to 149° C.

1. temperatureThereafter, to the mixture which was cooled to 5° C.
2. additionwas added gradually dropwise a solution
3. customprepared
4. additionAfter dropwise addition
5. customthe cooling bath was removed
6. stirringthe mixture was stirred for 5 hours at room temperature
7. additionThereto, 300 ml of a saturated aqueous solution of ammonium chloride was added
8. extractionThe reaction mixture was extracted with ethyl acetate repeatedly
9. washThe extract was washed with water
10. dry with materialthe resulting organic layer was dried over anhydrous sodium sulfate
11. filtrationSodium sulfate was filtered off with suction
12. concentrationthe filtrate was concentrated
13. customto yield 23.5 g of oily substance
14. customThis oily substance was separated
15. custompurified by flash column chromatography (silica gel: 800 g, eluate: hexane-ethyl acetate (3:1 by volume) mixture)