Gas‐phase pyrolysis in organic synthesis: New route for synthesis of functionally substituted imidazoles

1,2,3‐Triazolylpropanone was prepared and coupled with aryldiazonium salts yielding the corresponding arylhydrazones. Gas‐phase pyrolysis of the hydrazono derivative produced N‐arylamino‐2‐acetylimidazole as well as 2‐acetylimidazole. The latter is the product of further pyrolysis of the former.     

A new bipyrrole coupling reaction

Pyrrole 8 was converted to 10 in 4 steps, and 10 was coupled directly to bipyrroles 1 in a Sonogashira reaction, respectively at the 3,3′ positions.     

Studies with enamines and azaenamines: A novel efficient route to 6‐amino‐1,4‐dihydropyridazines and their condensed derivatives

1‐Arylhydrazonopyruvaldehydes 1 react with α,β‐unsaturated nitriles 2 to yield 6‐amino‐1,4‐dihydropyridazines 4 that are converted into pyridazinones 5 via refluxing in an acetic acid/hydrochloric acid mixture and into the ethylidenemalononitrile derivatives 6 on reflux with malononitrile in ethanolic/piperidine solution.