论文部分内容阅读
人们很久以前就想把没有治疗作用的右旋伪麻黄碱转化成具疗效的左旋麻黄碱。过去的文献上记载的转化方法有用盐酸转化法,德国伊默克药厂专利法等,但是实际上都不是很有效的方法。不久以前又有人介绍用氯化亚硫酰转化法,这个方法仍然不能令人满意,因为它的转化率不过是40%左右。最近生态晋氏发表先经乙酰化再经氯化的方法可以提高转化率到70%以上(自右旋-N-乙酰伪麻黄碱计算)。其方法如下:1.自右旋伪麻黄碱制备右旋-N-乙酰伪麻黄碱
People wanted to convert dextro-ephedrine, which has no therapeutic effect, into a therapeutic effect of levoephedrine a long time ago. The conversion methods described in the past literature include the hydrochloric acid conversion method, the German Imam Pharmaceuticals Patent Law, and the like, but they are actually not very effective methods. Not long ago, someone introduced the method of thionyl chloride conversion. This method is still unsatisfactory because its conversion rate is only about 40%. Recently, the method of acetylating and then chlorinating by Jinshi previously announced that the conversion rate can be increased to more than 70% (calculated from D-N-acetyl pseudoephedrine). The method is as follows: 1. Preparation of D-N-acetyl pseudoephedrine from D-pseudoephedrine