反应详情

1.7 g (0.0075 mol) of methyl 2-(2-hydroxyphenyl)-2-hydroxyimino-acetate (HPLC: 86.4% Z, log p=1.70) (Example VII-1d from process step 7) in 40 ml of acetonitrile are heated under reflux with 0.77 g (0.0076 mmol) of potassium bicarbonate and 1.1 g (0.0087 mol) of dimethyl sulphate for 10 hours. The reaction mixture is poured into water, the product is extracted with diethyl ether and the solvent is distilled off under reduced pressure. This gives 1.2 g of crude product which, according to HPLC, contains 46% of methyl Z-2-(2-hydroxyphenyl)-2-methoxyimino-acetate of log p=2.38. This crude product is chromatographed over silica gel using a mixture of 7 parts of n-hexane and 3 parts of acetone. This gives 0.8 g of a product which, according to HPLC, contains 54.4% methyl Z-2-(2-hydroxyphenyl)-2-methoxyimino-acetate of log p=2.39.

1. extractionthe product is extracted with diethyl ether
2. distillationthe solvent is distilled off under reduced pressure
3. customThis crude product is chromatographed over silica gel using
4. additiona mixture of 7 parts of n-hexane and 3 parts of acetone