Azolyl Derivatives of Nitrohalobutadienes: V. A New Route to Functionally Substituted Benzazetines

Heating of 1-azolyl-1-(4-R-phenylamino)-2-nitro-3,4,4-trichloro-1,3-butadienes and 1-azolyl-1-(4-R-phenylamino)-2-nitro-3,4-dichloro-4-bromo-1,3-butadienes (R = BuO, EtO, MeO, Me; azolyl = 1-benzotriazolyl, 3,5-dimethyl-1-pyrazolyl, and 1,2,4-triazol-1-yl) in methanol or acetic acid gave the corresponding 2-(1-nitrotrihalopropenylidene)-4-R-benzazetines. The latter reacted with amines, sodium alkoxides, and sodium thiolates, affording salts of the aci-nitro form. The reactions with benzoyl chloride and chloroacetyl chloride in the presence of pyridine led to formation of mixed anhydrides.