反应详情

To a solution of ethyl 2-methoxyimino-3,3-ethylenedioxy-4-chlorobutyrate (syn isomer, 7.3 g) in ethanol (35 ml) was added 1N aqueous solution of sodium hydroxide (35 ml) and the mixture was stirred for 2 hours at 40°-45° C. and then evaporated under reduced pressure. To the residue was added a saturated aqueous solution of sodium chloride (50 ml) and the mixture was washed with diethyl ether (60 ml). The aqueous layer was separated and then diethyl ether (100 ml) was added thereto. The mixture was adjusted to pH 1 with 10% hydrochloric acid, and the diethyl ether layer was separated and then the remaining aqueous layer was further extracted with diethyl ether (50 ml×2). The diethyl ether layer and extracts were combined together, washed with a saturated aqueous solution of sodium chloride, dried over magnesium sulfate and then the solvent was distilled off. To the resultant oil was added benzene, and the benzene was distilled off. The resultant solid was washed in ligroin, collected by filtration and then dried to give 2-methoxyimino-3,3-ethylenedioxy-4-chlorobutyric acid (syn isomer, 5.4 g), mp 80°-81° C. (Yield: 83.3%).

1. customevaporated under reduced pressure
2. additionTo the residue was added a saturated aqueous solution of sodium chloride (50 ml)
3. washthe mixture was washed with diethyl ether (60 ml)
4. customThe aqueous layer was separated
5. additiondiethyl ether (100 ml) was added
6. customthe diethyl ether layer was separated
7. extractionthe remaining aqueous layer was further extracted with diethyl ether (50 ml×2)
8. washwashed with a saturated aqueous solution of sodium chloride
9. dry with materialdried over magnesium sulfate
10. distillationthe solvent was distilled off
11. additionTo the resultant oil was added benzene
12. distillationthe benzene was distilled off
13. washThe resultant solid was washed in ligroin
14. filtrationcollected by filtration
15. customdried