作者:Ulf Ragnarsson、Bengt Fransson、Leif Grehn
DOI:10.1039/b000139m
日期:——
Substitutions under competition conditions are performed with a triprotected hydrazine reagent A as nucleophile and various halides as electrophiles and the product distribution determined by HPLC. Subsequently, after partial deprotection, stepwise substitution on the other nitrogen is studied similarly in order to define the scope of such reagents for the synthesis of libraries comprising multisubstituted hydrazines. In the course of this work a large number of partially protected hydrazine derivatives are prepared and characterized spectroscopically and chromatographically. The results indicate that n-alkyl and benzyl halides are of comparable reactivity under the conditions used, whereas others deviate too much in this respect as a result of which product mixtures severely distorted from equimolar ones are formed. In the course of this work, hydrazine libraries containing up to nine components are characterized quantitatively.
在竞争条件下,使用三保护氢肼试剂A作为亲核试剂,采用各种卤化物作为电亲和体进行取代反应,并通过高效液相色谱(HPLC)确定产物分布。随后,在部分去保护后,研究其他氮上的逐步取代反应,以明确这种试剂在合成包含多取代氢肼的文库中的适用范围。在此过程中,制备和表征了大量部分保护的氢肼衍生物,采用光谱学和色谱学方法进行分析。结果表明,n-烷基和苄基卤化物在所用条件下的反应性相当,而其他卤化物由于反应性差异过大,导致形成的产物混合物严重偏离等摩尔比。在此工作中,最多包含九个组分的氢肼文库经过定量表征。