Harry Adams, David E. Fenton, Shabana R. Haque, Masaaki Ohba and Hisashi Okawa
The reaction of 2-(chloromethyl)-6-formyl-4-methylphenol with 2,2′-dipyridylamine readily gave a 1-alkyl-2-{[1-alkylpyridin-2(1H)-ylidene]amino}pyridinium, the crystal structure of which was determined by X-ray crystallography.