SYNTHESIS OF BIS(o-HYDROXYPHENYL)-1,3,5-TRIAZINES, 1,2,4-TRIAZOLES, AND OXADIAZOLE BY RECYCLIZATION OF THE o-HYDROXYPHENYL-4-OXO-1,3-BENZOXAZINIUM CATION

Article abstract of DOI:10.1007/BF00513273

The acidic cyclization of disalicylamide gave 2-(o-hydroxyphenyl)- and 2-(o-acetoxyphenyl)-4-oxo-1,3-benzoxazinium perchlorates, by reaction of which with hydroxylamine, hydrazines, benzamidine, guanidines, and S-methylisothiourea bis(o-hydroxyphenyl)-1,2