The reactions of 3-formylchromone (1) with 1,2-phenylenediamine, 2-aminodiphenylamine and 2-aminophenol were reinvestigated and shown to yield 1,8dihydro-6, 13-di (2-hydroxybenzoyl)-dibenzo [b, i]-1,4, 8, 1 l-tetraazacyclotetradeca-4,6,11,13-tetraene (7), 3-[2-( 1-phenyl)benzimidazolyl]chromone (lob) and 3-(2-hydroxyphenyl)iminomethylchromone (4), respectively at variance with earlier reports. Compound 4 reacts with ethanol to give 2-ethoxy-3-[(2-hydroxyphenyl)-ami~omethylidene]chrornan-4-one (5b). Dehydrogenation of 7 produces 3-(2-benz-imidazoly1)chromone (loa), also at variance with earlier reports. The structures have been elucidated with the aid of NMR. and mass spectra. The reaction mechanism is discussed.Introduction. -3-Formylchromone (1) reacts with primary aromatic amines to give the anils 2. the C(2) atom of which is strongly activated towards nucleophilic substitution [ 1-41. Compounds 2 react e.g. with alcohols, thiols, secondary amines, anilines and water [3] to form compounds of type 3, some of which are rather unstable. K N / A 1 A r N H , -&H=NAr 0 5 aH 1 2 3 X = OR, SR, OH, NR2, NHAr These compounds 3 show a characteristic trans-vicinal coupling of 12-13 Hz between the olefinic and the amino proton [l]. Compound 1 also reacts with aromatic amines carrying an additional reactive group in the ortho-position (e.g. OH, NH2, NHCbHs, SH) [4] [5]. The reported [4][5] structure of the reaction product of 1,2-phenylenediamine with 1, however, differed from the results we obtained in the course of our studies on the synthesis of pyridines from 1 [6]. We