High-conversion (HC) copolymers of aniline and o-methoxyaniline (o-anizidine) were synthesized for the first time by chemical oxidative copolymerization using various polymerization techniques (simultaneous or consecutive introduction of comonomers into the polymerizing system). Low-conversion (LC) copolymers have also been synthesized for comparison. The polymers obtained were characterized using H-1-NMR, infrared, and electronic absorption spectroscopy, differential scanning calorimetry, and electrical conductivity measurements. Solubility characteristics and composition of different fractions of the copolymers were also determined. It was shown that in contrast to the LC copolymers, HC copolymers reveal relatively poor solubility. Electrical conductivity of copolymers and also of o-methoxyaniline homopolymer is lower compared to polyaniline, which correlates with notable hypsochromic (blue) shift of the bands in electronic absorption spectra. (c) 2005 Wiley Periodicals, Inc.