DIAZO COMPOUNDS OF THE HETEROCYCLIC SERIES. 4. SOME PECULIARITIES OF THE DIAZO COUPLING OF BENZIMIDAZOLE-2-DIAZONIUM SALTS WITH PHENOLS AND THEIR ETHERS

Article abstract of DOI:10.1007/BF00487430

The corresponding hydroxy (methoxy)-substituted azobenzimidazoles were obtained by diazo coupling of benzimidazole-2-diazonium salts with phenols and their complete and incomplete ethers in strongly acidic media; in the case of phenol ethers the process is complicated by dealkylation of the methoxy group in the ortho position relative to the diazo bridge.