Synthesis and oxidative cyclization of 3-amino-2-arylazo-5-tert-cycloalkylaminothiophenes
摘要:
A series of 3-amino-4-arylazo-4,5-dihydrothiophenes has been synthesized by the reaction of aryl-hydrazonocyanothioacetamides (containing a tert-cycloalkylamino group) with alpha-halo ketones, 2-chloroacetonitrile, or 4-nitrobenzyl bromide. Their oxidation in the presence of metal acetates was investigated. It was shown that heating in pyridine with Cu(OAc)(2) leads to the formation of thieno[3,4-d]-1,2,3-triazoliumolates.