反应详情

To a mixture of 2-(6-aminopyridin-2yl)-2-methoxyiminoacetic acid hydrochloride (syn isomer), acetic acid (350 ml.) and water (10 ml.) was introduced chloride gas for 1.5 hours. After the removal of the excess of the chlorine gas by bubbling air into the reaction mixture, the solvent was distilled off. The residue was pulverized in diethyl ether and collected by filtration. After the addition of water and ethyl acetate to the resultant powder (9.8 g.), the aqueous layer was separated and washed with ethyl acetate. The ethyl acetate layer and washings were combined together, and further extracted with water. The aqueous layers were combined together and adjusted to pH 4 with 1 N aqueous solution of sodium hydroxide, and then the solvent was distilled off under reduced pressure. The remaining water in the residue was azeotropically removed with benzene three times to yield brownish powder which was dried in a desiccator to give 2-(6-amino-3-chloropyridin-2-yl)-2-methoxyiminoacetic acid (syn isomer) (3.27 g.).

1. customAfter the removal of the excess of the chlorine gas
2. customby bubbling air into the reaction mixture
3. distillationthe solvent was distilled off
4. filtrationcollected by filtration
5. additionAfter the addition of water and ethyl acetate to the resultant powder (9.8 g.)
6. customthe aqueous layer was separated
7. washwashed with ethyl acetate
8. extractionfurther extracted with water
9. distillationthe solvent was distilled off under reduced pressure
10. customThe remaining water in the residue was azeotropically removed with benzene three times
11. customto yield brownish powder which
12. customwas dried in a desiccator