反应详情

Under an atmosphere of nitrogen, 6.00 g (20.32 mmol) of the 5-cyano-3-hydroxy-3-(2-ethoxypyridin-3-yl)-1,3-dihydroindol-2-one were suspended in 60 ml of anhydrous dichloromethane (dried over molecular sieve). 2.30 ml (28.45 mmol) of pyridine were then added. The reaction mixture was cooled to a temperature of 0° C., and 2.06 ml (28.45 mmol) of neat thionyl chloride were then added dropwise (exothermic reaction). The mixture was stirred at room temperature for one hour. The formation of a yellow suspension was observed. The course of the reaction was monitored by thin-layer chromatography (TLC) (silica gel, dichloromethane/methanol in a ratio of 95:5). The reaction mixture was carefully poured into ice-water. After 15 minutes of stirring, the organic phase was removed. The aqueous phase was extracted with dichloromethane (2×). All organic phases were combined, dried over magnesium sulphate and filtered, and the solvent was removed under reduced pressure. The product gave 5.70 g (18.17 mmol, 89%) of 3-chloro-3-(2-ethoxypyridin-3-yl)-2-oxoindoline-5-carbonitrile as an amorphous solid which was used without further purification for the next reaction.

1. additionwere then added dropwise
2. custom(exothermic reaction)
3. stirringAfter 15 minutes of stirring
4. customthe organic phase was removed
5. extractionThe aqueous phase was extracted with dichloromethane (2×)
6. dry with materialdried over magnesium sulphate
7. filtrationfiltered
8. customthe solvent was removed under reduced pressure