An efficient direct method for the azo-coupling of methoxythiophenes

The direct azo-coupling of methoxythiophenes with diazonium salts in good/excellent yield to give previously inaccessible methoxyazothiophenes is reported. The need to prepare potentially unstable methoxy-substituted aminothiophenes is avoided. Materials may be of potential use as photosensitive media for optical data storage and as disperse dyes.