Recyclization of 2-imino-2H-1-benzopyrans using nucleophilic reagents 3. Reaction of 2-iminocoumarin-3-carboxamides with o-phenylenediamines and o-amino(thio)phenols

Article abstract of DOI:10.1007/BF02317811

Using o-phenylenediamines, o-aminophenol or o-aminothiophenol, 2-iminocoumarin-3-carboxamide can be recyclized to the corresponding 3-(1H-benzimidazol-2-yl), 3-(benzoxazol-2-yl), or 3-(benzothiazol-2-yl) coumarins. An alternative synthesis has been carried out and an analytical comparison of the synthetic routes made.