title: Synthesis of a new series of pyridine and fused pyridine derivatives.
abstract: The reaction of 4-methyl-2-phenyl-1,2-dihydro-6-oxo-5-pyridine- carbonitrile (1) with arylidene malononitrile afforded isoquinoline derivatives 2a,b. 6-Chloro-4-methyl-2-phenyl-5-pyridinecarbonitile (3) obtained by chlorination of compound 1 with phosphoryl chloride was converted into 6-amino-4-methyl-2-phenyl-5-pyridinecarbonitrile (4) and 6-hydrazido-4-methyl-2-phenyl-5-pyridinecarbonitrile (5) in good yield, through reactions with ammonium acetate and hydrazine hydrate, respectively. Treatment of 4 with ethyl acetoacetate, acetic anhydride, formic acid, urea and thiourea gave the corresponding pyrido [2,3-d] pyrimidine derivatives 7–10a,b. A new series of 6-substituted-4-methyl-2-phenyl-5-pyridine carbonitriles 11–13 has been synthesized via reaction of 4 with phenyl isothiocyanate, benzenesulphonyl chloride and acetic anhydride. Treatment of 4 with malononitrile gave 1,8-naphthyridine derivative 14. The reactivity of hydrazide 5 towards acetic acid, phenylisothiocyanate and methylacrylate to give pyrazolo-[3,4-b]-pyridine derivatives 15–17 was studied. Treatment of 5 with acetic anhydride, phthalic anhydride and carbon disulphide gave pyridine derivatives 18,19 and 1,2,4-triazolo-[3,4-a]-pyridine derivative 20.
authors.affiliation: Chemistry Department, Faculty of Science, Princess Nora Bint Abdul Rahman University, Riyadh 11435, Saudi Arabia. sehamelissa@yahoo.com
authors.forename: Siham Abdulrahman
authors.initials: SA
authors.lastname: Al-Issa
mesh_terms: D055808:Drug Discovery; D006571:Heterocyclic Compounds / Q000737:chemistry*; D006834:Hydrazines / Q000138:chemical synthesis* / Q000737:chemistry*; D009570:Nitriles / Q000737:chemistry; D011725:Pyridines / Q000138:chemical synthesis* / Q000737:chemistry*; D011743:Pyrimidines / Q000138:chemical synthesis* / Q000737:chemistry*
chemical_list: D006571:Heterocyclic Compounds; D006834:Hydrazines; D009570:Nitriles; D011725:Pyridines; D011743:Pyrimidines; C000945:dicyanmethane