清洁生产技术在氯唑沙宗合成中的应用

Application of cleaner production in chlorzoxazone synthesis

针对国内外氯唑沙宗合成工艺复杂、成本高、污染严重等问题,采用清洁生产及绿色化学原理改进现有氯唑沙宗合成路线。水解反应无需进行固液分离,实现了水解和还原反应在一个反应釜内完成,减少了中间体损失。还原反应采用水合肼取代二硫化钠,反应较温和,选择性好;副产物是氮气和水,母液中硫化物近似为0 mg/L,COD质量浓度降为3 000—5 000 mg/L。产品总收率为84%,产品质量符合USPXX IV,实现了氯唑沙宗的清洁生产和污染预防。

According to the special features of synthesizing chlorzoxazone home and overseas, including complicated techniques, expensive cost and severe pollution, the new synthetic process was used in order to improve the existing technology of manufacturing chlorzoxazone in the light of the principles of cleaner production and pollution prevention. During the experiment, hydrolysis and reduction were implemented in one-pot, which is close reaction and reduces the losses of intermediates. In reduction reaction, hydrazine was used to replace natrium disulfides, which has moderation and better selectivity; the byproduct is water and nitrogen gas. The waste water of acentric sedimentation contains sulfide which is approximately 0 mg/L;COD mass concentration drops to 3 000-5 000 mg/ L. By the cleaner production of chlorzoxazone, the total yield is about 84% , and the quality of products is according with USPXXIV. The cleaner production and industrial pollution prevention of chlorzoxazone is obtained.