Synthesis Of New Technology For M By Nitrobenzene Method And DM By Oxygen As Oxidant

Synthesis of new technology for 2-mercaptobenzothiazole by nitrobenzene method and 2,2-dibenzothiazyl disulfide using oxygen as oxidant were focused.2-mercaptobenzothiazole (M) possessed accelerated effect as an important kind of all-purpose rubber accelerator, which was also the material for synthesizing many rubber accelerators, intensifier for plastic and pharmaceutical intermediate. The paper focused on synthesizing M using nitrobenzene method that was nitrobenzene partly or entirely instead of aniline with carbon bisulfide and sulphur in the high-pressure reacter deoxidized by sulfureted hydrogen from aniline method's outgrowth on the basis of aniline method. It studied the craftwork more systemically and detailedly, achieved the better technical conditions.The better technical conditions for nitrobenzene partly instead of aniline were: temperature 250°C, pressure 5.0~ 6.0MPa, time 3h according to single factor experiments and orthogonal experiment. The molar proportion of aniline and nitrobenzene was 5: 1 ~ 1: 1 and the average yield achieved 85%. Only the proportion lying in 5: 1~3: 1 was up to the mustard. After refining, the product could be fine-class. The better technical conditions for nitrobenzene entirely instead of aniline were:slowly heated and the maximal temperature was below 210°C. It could be out controlled when the condition exceeded the temperature because of rapidly hoist of temperature and pressure. Also, the product become black solid and the yield was very low, v.v. Whereas the grindingly conditions, it only made a certain extent progress. The product's structure was testified exactly by IR.The better technical conditions for synthesizing M: nitrobenzene could be deoxidized partly to aniline by sulfureted hydrogen were: temperature 80~100°C and time 3~4h, then added carbon bisulfide which contained sulphur into the system deoxidized directly. The progress was carried through according to niline-nitrobenzene method, so the pressure and the temperature was lower which reduced the spoilage to the facilities.2,2-dibenzothiazyl disulfide(DM) possessed accelerated effect as an important kind of all-purpose rubber accelerator for caoutchouc, synthetic rubber, rebirth rubber, which was also a king of pharmaceutical intermediates. It's sulfuration temperature was 130°C. When the temperature was above 140°C, the activity increased with the remarkable after effect and security handled. This thesis focused on the synthesizing DM with the raw material M refined, ammonia as solvent and the oxygen as oxidizer which was green and economical. The better technical conditions obtained.The better technical conditions of oxygenation method using oxygen as oxidizer were: 5% ammonia, temperature 50~60°C, pressure 0.7MPa, A as catalyzer which mass was 2% of raw material M. The average yield was 87.1% and the average melting point was 177.6°C. The progress met international leading level. The product's tructure was testified exactly in IR.The better technical conditions of refining DM were: combine the extraction way with the crystal way so that 2,2-Dibenzothiazyl Disulfide(DM) could be refined. Examine its purity by using the method which measures melting point. It obtained the following conclusions with the experiment, joining the quantity of solvent toluene and crude DM by 7:1 in proportion, establishing temperature in 120°C, then cooling, crystallizing and drying. It obtained the light white crystal. The melting point could achieve 183°C, the yield reached 92%.The thesis also completed the trial-production of new progress in the factory on the basis of the research in the laboratory, got through the technical flow and obtained the better technical conditions. The conditions were as follows: 5% ammonia, the mol ratio 4: 1 between ammonia and raw M, temperature for solving 50~85°C, emperature for oxidation 60°C, pressure for oxidation 0.5~0.8MPa, time for oxidation 3h. The yield reached 98%. The new progress didn't appear in the papers published.