Abstract
2,6-Bis (beta -aryl-acryloyl) pyridines (2) were newly synthesized and reacted with phenylhydrazine, guanidine or thiourea to yield the corresponding pyrazole, aminopyrimidine and thioxypyrimidine derivatives 3-5, respectively. Compounds 5 were condensed with bromoacetic acid or 3-bromopropanoic acid to yield the thiazolopyrimidine 6 and thiazinopyrimidine derivatives 7, respectively. Compounds 5 were again condensed with bromoacetic acid and aromatic aldehydes to yield the arylmethylene derivatives 8, which could be prepared directly by condensation of compound 6 with aromatic aldehydes.
Compounds 2 were condensed with malononitrile or ethyl cyanoacetate in presence of ammonium acetate to yield cyanopyridine and cyanopyridone derivatives 9,10, respectively, which were prepared by condensation of 2,6-diacetylpyridine (1), molononitrile or ethyl cyanoacetate and aromatic aldehydes in presence ammonium acetate.
2,6-Bis- (substituted-benzodiazepino) pyridine derivatives 11 were obtained by condensation of compounds 2 with o-phenylenediamine in refluxing butanol, followed by cleavage by thermolysis to benzimidazole derivatives 12 along with compound 13 as mixture, which were obtained directly by fusion of alpha-beta -unsaturated ketones 2 with o-phenylenediamine at 200-210 degrees, while, compound 12 could be prepared in pure form by fusion of 2,6-diacetylpyridine 1 with o-phenylenediamine at the same temp.