Ring transformations of heterocyclic compounds. XVII, 2-(2,4,6-Triarylphenyl) substituted dihydro-1<i>H</i>-imidazolium, dihydrothiazolium and thiazolium salts from 2-methyl derivatives by pyrylium and thiopyrylium ring transformations
作者:Thomas Zimmermann
DOI:10.1002/jhet.5570360339
日期:1999.5
The synthesis of hitherto unknown 2-(2,4,6-triarylphenyl) substituted 4,5-dihydro-1H-imidazolium perchlorates 6, 4,5-dihydrothiazolium perchlorates 8 and thiazolium perchlorates 9 from their 2-methyl derivatives 2, 4 and 5, respectively, by a 2,6-[C5+C] ringtransformation of 2,4,6-triarylpyrylium and -thiopyrylium salts 1/10 in ethanol in the presence of an appropriate base (6: sodium ethanolate;