反应详情

89.25 grams (0.7 mole) of thionyl chloride at +5° C. were slowly dropped into a solution of 137.0 grams (0.59 mole) of 6-hydroxy-8-methylthiooctanoic acid ethyl ester (VIb) and 1 ml of pyridine in 300 ml of dichloromethane. After stirring for 1 hour at +10° C. the mixture was heated for 3 hours at reflux and subsequently concentrated in a vacuum. The residue was treated with 200 ml of water and extracted with dichloromethane. After drying the combined extracts with sodium sulfate the solvent was removed in a vacuum. By fractional distillation there were obtained 125.1 grams (84% of theory) of 6-chloro-8-methylthiooctanoic acid ethyl ester as a colorless oil having a boiling point of 135° C. to 145° C. at 1 mbar.

1. temperaturewas heated for 3 hours
2. temperatureat reflux
3. concentrationsubsequently concentrated in a vacuum
4. additionThe residue was treated with 200 ml of water
5. extractionextracted with dichloromethane
6. dry with materialAfter drying the combined extracts with sodium sulfate the solvent
7. customwas removed in a vacuum
8. distillationBy fractional distillation there