Abstract
The structure of the red product of the Fujiwara reaction was investigated by using chloroform as a gem-polyhalogen compound. Isolation of the product followed by nuclear magnetic resonance and mass spectroscopic analysis revealed the red chromophore to be the sodium salt of N1, N2-bis [(1E, 3E)-4-formyl-1, 3-butadien-1-yl] formamidine. The structure of the red products formed from trichloroacetic acid and chloral hydrate were also investigated. High-performance liquid chromatography analysis and mass spectra showed that both products have the same structure as that from chloroform. Since the red product from benzotrichloride has an analogous spectrum, it is concluded that the structure of the red produots formed from the series of trichloroalkyl compounds (RCCl3) is the nitrogenated polyene produced by the ring cleavage of two pyridine rings.
