| 摘要 |
Pure crystalline racemic sodium parahydroxymandelate free from any ions of chloride, acetate, formate and sulfate group, is manufactured by condensing in water, in the presence of sodium hydroxide at a temperature between 30 DEG and 100 DEG C., glyoxylic acid or sodium glyoxylate with an excess of phenol, concentrating it hot, until the start of crystallization of the solution thus obtained after neutralization and removal of the unconverted phenol either by steam distillation, or by extraction with a water-immiscible organic solvent. The resulting suspension obtained is cooled, drained after some hours of standing at a temperature close to 5 DEG C., and the resulting precipitate recovered by washing it with iced water followed by drying to constant weight. The product is useful for the manufacture of crystalline sodium paraformylphenolate.
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