Thermal and Photochemical Transformations of 1-(Arylazo)-N-arylidene-2-naphthylamines

Article abstract of DOI:10.1021/jo01304a008

1-(Arylazo)-N-arylidene-2-naphthylamines 3a-e, prepared by the reaction of 1-(arylazo)-2-naphthylamines 1a,b with aromatic aldehydes 2a-d on refluxing in toluene, gave the corresponding 1-(arylamino)-2-phenylnaphth<1,2-d>imidazoles 6a-e in yields ranging between 50 and 60percent.Refluxing of 3a in o-dichlorobenzene, however, gave 1H-2-phenylnaphth<1,2-d>imidazole (7, 45percent) and 2H-2-phenylnaphtho<1,2-d>triazole (9, 5percent).Reaction of 3a with dimethyl acetylenedicarboxylate gave dimethyl benzoquinoxaline-2,3-dicarboxylate (10, 11percent), dimethyl-α-benzal-α'-<<1-(phenylazo)-2-naphthyl>imino>succinate (11, 7percent), dimethyl <1-(phenylazo)-2-naphthyl>aminofumarate (12, 2percent), and benzanilide (13, 6percent).The reaction of 1-(phenylazo)-2-naphthylamine (1a) with DMAD, however, gave 10 (32percent) and 12 (3percent).Photolysis of 3a in benzene gave 2H-2-phenylnaphtho<1,2-d>triazole (9, 5percent) and N-benzoyl-1-(phenylazo)-2-naphthylamine (19, 41percent), whereas the photolysis in methanol gave a mixture of 6a (10percent), 19 (25percent), 1a (1percent), and the naphthotriazole 9 (4percent).Reasonable mechanisms have been suggested for the formation of the various products in these reactions.