参考文献如下: 143.6 g (one mole) of 2-chloro-6-methoxy-pyridine were added dropwise with stirring over one hour to a mixture of 1600 ml of concentrated sulfuric acid and 800 ml of fuming nitric acid cooled to 0.deg. C. and the temperature was allowed to rise to 20.deg. C. over three hours. The mixture was then stirred at 20.deg. C. for three hours and was poured into 5000 g of crushed ice. The mixture was vacuum filtered and the product was washed with a large volume of water until acid free and dried to obtain 151-156 g (80-83percent yield) of 2-chloro-3nitro-6-methoxy-pyridine in the form of yellow crystals melting at 67.deg. to 69.deg. C. with a purity of 84 to 85percent. 我小试了几次,每次都是刚开始的三个小时反应挺好的,就一个新点生成,可是过了三个小时就会多一个点出来,如果三个小时处理的话可以拿到纯的产品,就是收率低. 各位有没有遇到过类似的情况?大家给点意见!
