On the coupling of aryldiazonium salts with N,N-disubstituted 2-aminothiophenes and some of their carbocyclic and heterocyclic analogues
Abstract
As exemplified with the morpholino derivatives 7, N,N-disubstituted 2-aminothiophenes couple, depending on the substitution pattern at C(5), with aryldiazonium salts 1 either at their C(3) or C(5) position yielding the corresponding 3-arylazo-2-morpholinothiophenes 9 or, under elimination of the substituent at C(5), 5-arylazo-2-morpholinothiophenes 10. This reaction contrasts to the behaviour of 5-morpholinothiazoles 8 and