[CH2:1]([O:5][C:6]1[CH:14]=[CH:13][CH:12]=[CH:11][C:7]=1[C:8](O)=O)[CH:2]([CH3:4])[CH3:3].S(Cl)(Cl)=O.[N+](=C)=[N-].CN(N=O)[C:24](N)=[O:25].[OH-].[K+].Cl.[CH2:32]([O:34]CC)C>C(Cl)Cl.CO.C([O-])(=O)C1C=CC=CC=1.[Ag+].O.C(OCC)(=O)C.C(N(CC)CC)C.C(O)(=O)C>[CH2:1]([O:5][C:6]1[CH:14]=[CH:13][CH:12]=[CH:11][C:7]=1[CH2:8][C:32]([O:25][CH3:24])=[O:34])[CH:2]([CH3:4])[CH3:3]In 40 ml of methylene chloride are dissolved 3.8 g of 2-isobutoxybenzoic acid and 2.8 ml of thionyl chloride. The solution is heated under reflux for one hour with stirring. The reaction mixture obtained herein is dropwise added at 5-10° C. to a solution of diazomethane in ethyl ether prepared from 53.0 g of N-methylnitrosourea, 83.0 g of potassium hydroxide, 120 ml of water and 150 ml of ethyl ether, and the mixture thus obtained is stirred at ambient temperature for 2 hours. Ethyl ether, acetic acid and water are added to the reaction mixture, and the organic layer is separated. The organic layer thus obtained is washed with water and saturated aqueous solution of sodium chloride successively and dried over anhydrous magnesium sulfate, and then the solvent is distilled off under reduced pressure. The residue thus obtained is dissolved in 30 ml of methanol, and the resulting solution is added to a mixture of 2.3 g of silver benzoate and 23 ml of triethylamine at 25-30° C., and stirred for 1.5 hours. Ethyl acetate and water are added to the reaction mixture, pH is adjusted to 2.0 with concentrated hydrochloric acid, and the organic layer is separated. The organic layer thus obtained is washed with water and saturated aqueous solution of sodium chloride successively and dried over anhydrous magnesium sulfate, and then the solvent is distilled off under reduced pressure. The residue is purified by silica gel column chromatography (eluent; n-hexane:ethyl acetate=9:1) to obtain 3.8 g of methyl 2-(2-isobutoxyphenyl)acetate as a colorless oily product.
読み込み中…
