| 摘要 |
PURPOSE:To crystallize and separate the subject compound in the form of sodium salt by oxidizing p-cresols in methanol, adding water to the resultant reaction mixture, as necessary, filtering the mixture, then distilling away the methanol, subsequently neutralizing the obtained mixture and cooling the neutralized mixture. CONSTITUTION:p-Cresols are oxidized with oxygen or an oxygen-containing gas in the presence of a catalyst containing sodium hydroxide and a cobalt compound in methanol and water is then added to the resultant reaction mixture. The obtained mixture, as necessary, is filtered to separate tar components, catalyst, etc. The produced solution is then heated to 50-100 deg.C temperature to distill away the methanol. The resultant solution is subsequently neutralized to pH9-11 and, as necessary, extracted with a solvent (the unreacted m-cresol, etc., are separated when mixed m-/p-cresol is used as a raw material) and the solution temperature is then cooled to -20 to +50 deg.C, preferably 0-20 deg.C to crystallize and separate the objective compound in the form of Na salt. The separated crystals are subsequently dissolved in water, as necessary, filtered and neutralized with a mineral acid to crystallize and separate the objective compound. |
