| 摘要 |
PURPOSE:Seed crystals are added to crude chloracetaldehyde aqueous solution at room temperature, the mixture is cooled down to effect crystallization whereby the titled compound of high purity which is used as an intermediate of dyes, medicines and agrochemicals is obtained. CONSTITUTION:Before crude chloracetaldehyde aqueous solution (preferably the concentration is previously adjusted to 45-75%, particularly to 55-65%) is cooled down, seed crystals of chloracetaldehyde hydrate are added to the aqueous solution at room temperature in an amount of 0.05-0.5% based on the solution. Then, the mixture is cooled down to -5-5 deg.C under stirring to effect crystallization and the formed crystals slurry is filtered, as it is kept at about 0 deg.C, to separate the crystals of chloracetaldehyde hydrate. The filtrate can be reused to increase the total yield.
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