Pyridines 4-subst

Bis-[dimethyl-glyoximato]-pyridin-(2-subst.-4-tetrahydrofurylmethyl)-E19a, 851 (En + Co-Komplex) (l,2-Bis-[2-oxy-benzylidenamino]-benzol)-(perfluor-alkyl)- XIII/9b, 124... 

Benzenesulfonyl chloride pyridine Subst. carboxylic acid amides from carboxylic acids... 

Azine, This term has the following meanings a)Pyridine(Ref 2) b)Sym di-ylidene derivs of hydrazones of ketones or aldehydes, such as acetone azine. (CHj CiN-N CfCHj) (Ref 3) c)The group (Ns)a is called free azine" or nitrine. According to Walden Audrieth (Ref 1), the halides of azine are extremely expl substs which undergo spontaneous de-compn at RT... 

Pyrido[2.3-d]pyridin 3-Cyan-4,5-diamino-2-hydroxy-8-phenyl-E9c, 19 [2-(CO —CHj)—3-CN — subst.-py + N2H4]... 

Amino-2-(l-subst.-lH-tetrazol-5-ylthio)-pyridine ergeben mit ethanolischer Salzsaure (Riick-fluB) in Abhangigkeit vomSubstituenten amTetrazol-Ring2-(subst.-Amino)- pyrido[3,2-d]-1,3-thiazole> oder 2-Mercapto-3-(l-subst.-lH-tetrazol-5-ylamino)-pyridine78 ... 

Depending on the catalyst, either subst. quinolizidines or 4-ketoquino-lizidines may be obtained by reductive cyclization of pyridine derivatives, prepared by Michael addition of active methylene compounds to 2-vinylpyridine. E A mixture of diethyl / -(2-pyridyl)ethylmalonate, Raney-Ni, and ethanol heated 1 hr. at 145° under a H2-pressure of 200 atm. —> 3-earbethoxy-4-ketoquinolizidine. Y 97%. (V. Boekelheide and S. Rotehild, Am. Soc. 71, 879 (1949).)... 

Zur Herstellung von Thiobenzoesdure- und subst. Thiobenzoesdure-O-ethylestern (74 95%) aus Aryl-nitrilen s.Lit.102. Aus 2,5-Dicyan-pyridin erhalt man fiber das Bis-carbon-saure-methylester-imid das orange 2,5-Bis-(methoxy-thiocarbonyl)-pyridin (50%)1O2a. 

Lithium ammonia ethanol N-Subst. 1,4-dihydropyridines from pyridines... 

N-Subst. pyrrolidines. A 10 M soln. of BH3-dimethyl sulfide in THF added dropwise via syringe to a soln. of startg. succinamic ester in the same solvent under N2, the mixture refluxed 7-9 h, and quenched with methanol and 2 N NaOH N-phenylpyr-rolidine. Y 82%. The method failed for highly hindered amines. F.e. incl. N-subst. piperidines s. M.C. Venuti, O. Ort, Synthesis 1988, 985-8 review of pyrrole, pyrrolidine, piperidine, pyridine and azepine alkaloids (1986-7 literature) s. A.R. Pinder, Nat. Prod. Reports 6, 67-78 (1989). 

Fused pyridines. 1-Ethynylcyclopentanol added dropwise with stirring to a mixture of acetyl chloride and a little ZnCl2 and POCI3 at 0° (exothermic to 35-40°), cooled to 20°, stirred for 1 h, and the mixture poured into 23% aq. NH4OH at 0° - 2-methyl-3,4-cyclopentenopyridine. Y 55% (85-93% with acetyl bromide or iodide). F.e.s. F.A. Selimov et al., Izv. Akad. Nauk SSSR Ser. Khim. 1988, 2604-7 2,4-dialkyl-, 2,3,4-trialkyl-, and 2,4-diaryl-pyridines (without POCI3), also 2,3,4,6-tetra-subst. pyridines from 1,3-enynes, s. ibid. 2600-4. 

Bis(pentafluorophenyl) sulfite added to a soln. of N-r rFbutyloxycarbonylglycine in DMF containing 1 eq. pyridine, and stirred for 0.1-1 h at 20° - product. Y 96% (70% from pentafluorophenol with DCCI as condensing agent). There was no racemization with a-subst. derivs. F.e.s. A.V. Hina et al., Izv. Akad. Nauk SSSR Ser. Khim. 1988, 2816-8 with methyl pentafluorophenyl carbonate cf. Izv. Akad. Nauk LatvSSR Ser. Khim. 1988, 624. 

Isonicotinoyl amide in 0.8 N HGl electrolyzed at 5° and a cathode potential of —0.80 V vs. S.C.E. until 2 electrons per molecule are consumed 4-pyridine-aldehyde. Y 87% by polarographic determination. F. e., also reduction of subst. amides, s. H. Lund, Acta Ghem. Scand. 17, 2325 (1963). 

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