The Chlorzoxazone Cleaner Production And Pollution Prevention Research,

In this dissertation, the technology of cleaner production and industrial pollution prevention of chlorzoxazone has been studied. According to the special features of synthesizing chlorzoxazone home and overseas, including complicated techniques, expensive cost and severe pollution. The new synthetic process is put forward in order to improve on the existing technology of manufacturing chlorzoxazone in the light of the principles of cleaner production and pollution prevention. On the base of the above-mentioned theories, chlorzoxazone has been synthesized, the medicament accords with pharmacopoeia, while achieving the cleaner production of chlorzoxazone.During the experiment, hydrolysis and reduction have been implemented in one-pot, which is close reaction, reduces the losses of intermediates. The technical process of replacing C6H3ClNO3Na with C8H4C1N03 is much better than old one. Moreover, the atomy economy increases; meanwhile, the environment effect decreases. This experiment need not consume sodium chloride to reduce the 4-chloro-2-nitrophenol solubility. The working procedure of hydrolysis may participate in reduction process without being liquid-solid separation; consequently there is no waste water to bring contamination.In reduction reaction, Hydrazine was used to replace natrium disulfides without any pressure, and the reaction condition is moderation and better selectivity. The reaction byproduct is water and nitrogen gas, which do no harm to environment. The waste water of acentric sedimentation contains sulfide concentration which is approximately 0;COD amounts to from 3, 000 to 5, 000 mg/L, lightening the burden on contamination treatment.With C6H12O2 being abolished in the reduction-synthesize reaction, the late-model catalyzer30%HCl instead of 98%H2SO4 is employed which increases reaction velocity, decreases reaction time and improves work efficiency. Chlorzoxazone yield increase from 64% to 73%. Therefore, product costdecrease is about 15%. COD is near 1 OOOmg/L, basically according with the 3rd emission control regulations of the industrial pharmacy.When refining chlorzoxazone, the late-model activated carbon fiber (ACF) sorbent substitute active carbon powder, abolishing its dust pollution. Alcohol solvent is about 60%, and waste- water concentration is 45% which can be recycled. By this means the qualities of chlorzoxazone improve, reducing refine times, saving alcohol and preventing chlorzoxazone from loss, thereby the loss can be decreased.By new synthetic process of chlorzoxazone, the yield increases 15%. The cleaner production and industrial pollution prevention of chlorzoxazone have been obtained, accomplishing the GMP criterion of material medica workshop and acquiring the harmony of economy and environment.