الفهرس | Only 14 pages are availabe for public view |
Abstract Synthesis of Some New Pyridines Abd elraheem Mohammed Ahmed Mahmoud (Chemistry Department, Faculty of Science, Sohag, Egypt) The reaction of compound 1 with halo reagents namely; 1,2-dibromoethane, 1,3-dibromopropane, 1,4-dibromobutane, 2,3-dichloronaphthoquinone, tetrachlorobenzoquinone, ethyl chloro-acetate, chloroacetonitrile, phenacyl bromide or 2-chloroacetamide under PTC conditions gave products 2 - 15, respectively. When Compound 1 was allowed to react with dimethyl sulphate, triethyl orthoformate, acrylonitrile, chloroacetyl chloride, ethyl cyanoacetate, formamide or formic acid gave compounds 16 - 22 respectively. Acetylation of compound 1 using acetic anhydride afforded compound 23 which in turn underwent cyclization in pyridine to give compound 24. Under PTC conditions compound 16 was allowed to react with dihalo reagents namely; 1,3-dibromopropane, 1,4-dibromobutane, 2,3-dichloronaphthoquinone, tetrachlorobenzoquinone to give compounds 25 - 28 respectively. Treatment of compound 16 with 2,5-dimethoxytetrahydrofuran, potassium permanganate, hydrazine hydrate, thioacetamide or acetic anhydride afforded compounds 29 - 33 respectively. Also under the same PTC condition, compound 16 was treated with diethyl malonate, ethyl cyanoacetate, phenylisothiocyanate, ethyl bromoacetate, phenacyl bromide or 2-chloroacetamide to give compounds 34, 35, 37 - 41 respectively. Diazotization of compound 16 using sodium nitrite gave compound 36. Compound 30 was reacted with hydrazine hydrate, phenyl hydrazine, urea, thiourea or guanidine hydrochloride to give compounds 42 - 46 respectively. Reaction of compound 17 with phenyl hydrazine or benzohydrazide afforded compounds 47 or 48 Compound 11 was treated with sodium nitrite or 2,5-dimethoxytetrahydrofuran to give compounds 49 or 50 respectively. Keywords: pyridines, pyridine-2-thione, thieno[2,3-b]pyridine, pyrido[2,3-d]pyrimidine, 1,8-naphthyridine, imidazo[1,2-a]pyridine, pyrrolo[2,3-b]pyridine, pyrazolo[3,4-b]. |