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

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. For Communication 2 see 2]. Ukraine Pharmaceutical Academy, Khar'kov 310002. E-mail: kosn@ukrfa.kharkov.ua. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1664–1667, December, 1998.