反应详情

Into the cathode chamber of an electrolytic cell divided with a diaphragm (ceramic filter) was placed a solution of 10 mmols of methyl p-methoxyphenylacetate, 12 mmols of methyl iodide and 2.0 g of tetraethylammonium perchlorate in 30 ml of anhydrous dimethylacetamide. And the anode chamber was provided with a solution of 3.0 g of tetraethylammonium perchlorate in 20 ml of anhydrous dimethylformamide. Constant current electrolysis was performed at 0.2 A/cm2 with use of platinum for both the anode electrode and the cathode electrode. After passing 1.5 F of electricity per mol of the methyl p-methoxyphenylacetate through the solution at -5° to 0° C., the cathode solution was added to a saturated aqueous solution of ammonium chloride and the mixture was extracted twice with ether. The ether was distilled off and the residue was purified by silica gel column chromatography using hexane-ethyl acetate (10:1), giving methyl α-methyl-p-methoxyphenylacetate in a yield of 81% and α-methyl-p-methoxyphenylacetic acid in a yield of 10%. The spectral data of the ester were as follows.

1. filtrationInto the cathode chamber of an electrolytic cell divided with a diaphragm (ceramic filter)
2. customat -5° to 0° C.
3. extractionthe mixture was extracted twice with ether
4. distillationThe ether was distilled off
5. customthe residue was purified by silica gel column chromatography