Unexpected Dealkylation During Nucleophilic Substitution: Synthesis of 2-N,N-Dialkylamino Benzoxazoles and Benzothiazoles
作者:Abedawn I Khalaf、Ricardo G Alvarez、Colin J Suckling、Roger D Waigh
DOI:10.1016/s0040-4020(00)00802-4
日期:2000.10
and benzothiazoles from 2-chlorobenzoxazole and 2-chlorobenzothiazole and N-methyl or other simple N-alkyl tertiary amines. The reaction proceeds neat or in THF solution and involves dealkylation of the amine reactant by nucleophilic substitution by chloride. In the case of N-methylpyrrolidine and N-methylpiperidine demethylation was not observed and the major product was formed by ringopening to give
描述了由2-氯苯并恶唑和2-氯苯并噻唑和N-甲基或其他简单的N-烷基叔胺制备许多2-烷基-和2-芳基氨基苯并恶唑和苯并噻唑的温和反应条件。反应在纯溶液中或在THF溶液中进行,并且涉及通过氯化物的亲核取代使胺反应物脱烷基。在N-甲基吡咯烷和N-甲基哌啶未观察到脱甲基的情况下,通过开环形成主要产物,得到氯丁基-和氯戊基-甲基氨基取代的苯并恶唑和苯并噻唑。在丙酮中用碘化物处理氯丁基衍生物,得到新的1 H,2 H,3H,4 H,5 H- [1,3]二氮杂[2,1- b ] [1,3]苯并恶唑-6-鎓环系统。