Facile Preparation of Thiazoles
from 1<i>H</i>-1-(1′-Alkynyl)-5-methyl-1,2,3-benziodoxathiole
3,3-Dioxide with Thioamides
作者:Hideo Togo、Yoshihide Ishiwata
DOI:10.1055/s-0028-1083439
日期:——
Thiazoles were obtained in high yields by the reaction of 1H-1-(1′-alkynyl)-5-methyl-1,2,3-benziodoxathiole 3,3-dioxides, which were easily prepared from the reaction of 1H-1-hydroxy-5-methyl-1,2,3-benziodoxathiole 3,3-dioxide and 1-alkynes, with thioamides. Here, the co-product, potassium 2-iodo-5-methylbenzenesulfonate, was recovered quantitatively by simple filtration of the reaction mixture, and was regenerated to 1H-1-(1′-alkynyl)-5-methyl-1,2,3-benziodoxathiole 3,3-dioxides to be reused for the same preparation of thiazoles, keeping good yields.
通过1H-1-(1′-炔基)-5-甲基-1,2,3-苯并碘氧硫杂环戊烷3,3-二氧化物与硫酰胺的反应,可以高产率地获得噻唑类化合物。这些1H-1-(1′-炔基)-5-甲基-1,2,3-苯并碘氧硫杂环戊烷3,3-二氧化物很容易通过1H-1-羟基-5-甲基-1,2,3-苯并碘氧硫杂环戊烷3,3-二氧化物与1-炔的反应制备得到。在此过程中,副产物——2-碘-5-甲基苯磺酸钾——通过简单过滤反应混合物即可定量回收,并可再生为1H-1-(1′-炔基)-5-甲基-1,2,3-苯并碘氧硫杂环戊烷3,3-二氧化物,再次用于相同噻唑的制备,保持良好的产率。