Synthesis Of 2-cyanopyrazine

The applications of 2-cyanopyrazine and its derivatives in pharmaceutical, agricultural chemicals and spices were introduced. And then the research situation, market foreground and research purpose were discussed.2-Cyanopyrazine prepared from 2-methylpyrazine by ammoxidation is the most advanced way after all datas about synthesis about 2-cyanopyrazine and 2-methylpyrazine refered.The VPO catalyst was choosen for the ammoxidation reaction.The mechanism of 2-cyanopyrazine prepared from 2-methylpyrazine by catalytic ammoxidation was studied and explained with the theory of appropriate structure of group. Factors effecting the performance of VPO catalyst such as reducer, molar ratio of P and V, catalyst promoters like phosphorus(P) , chrome(Gr), kalium(K), molybdenum(Mo) and the supports of catalyst were investigated through experiments. The VPO catalyst with 1.4 molar ratio of P/V, and with activated alumina(Al₂O₃) with MoO₃ as support prepared by impregnation method has good performance both in activity and selectivity. Reaction factors such as reaction temperature, space velocity, feed composition and the service life of catalyst were investigated. 0.2 h^-1 of the space velocity , 380℃ of the reaction temperature and 1:7.8:8:8 molar ratio of 2-MP,water, oxygen and ammonia are optimum reaction condition ,and the selectivity could reach 92% and the yield could reach 85%. GrVPO catalyst also hasgood performance with 0.8:1.4:1 molar ratio of Gr ,V and P and with activated alumina as support. When 0.2h^-1 of the space velocity , 360℃ of the reaction temperature and 1:6:8:6 molar ratio of 2-MP,water, oxygen and ammonia, the selectivity could reach 89.36% and the yield could reach 80.65 % . Amidopyrazine was the main production in the experiments with MoVPO as catalyst which could be explained by the mechanism we have supposed.The circulated bed with reactor riser was designed to solve the problems of the reaction in fixed bed.The reaction in fixed bed will emit a lot quantity of heat in industrialization which is disadvantageous and easy to explode. The selectivity and conversion could be both enhanced in the circulated bed with reactor riser which could not be achieved in the fixed bed.