Syntheses of some novel imidazolidinethiones and condensed imidazoles containing arylazo moieties starting from cyanothioformamides

Cyclocondensation of cyanothioformamides (1) with arylhydrazonomalononitriles (2) afforded the novel imidazole derivatives (4a–e) in good yields. Isothiocyanatoazobenzene (6) was allowed to react with potassium cyanide and gave the new cyanothioformamide (7) which was reacted with 4-chlorophenyl isocyanate to yield imidazolidinethione (8). Compound (8) was subjected to react with hydrochloric acid, o-phenylenediamine, 4-methylaniline, and hydrogen sulfide and furnished compounds (10), (11), (12), and (15), respectively. Also, the reactivity of thiohydantoin (15) toward some electrophilic reagents such as N,N-dimethylformamide-dimethylacetal and arylidene-malononitriles was investigated. The structure of the synthesized compounds was established by analytical and spectral data. © 2005 Wiley Periodicals, Inc. Heteroatom Chem 16:218–225, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20113