3- Cyano-2-pyridones, formation

N-Cyanoguanidine, 35, 69 Cyanohydrin formation, 33, 7 3-Cyano-6-isobutyl-2(l)-pyridone, 32, 34 3-Cyano-6-methyl-2(1)-pyridone, 32, 32 l-Cyano-3-a-naphthylurea, 36, 11 1-Cyano-3-phenylurea, 36, 8 Cyclic acyloins, 36, 82 Cyclization, (3-aminoethylsulfuric acid to ethylenimine, 30, 38 1,2-benzo-3,4-dihydrocarbazole from phenylhydrazine and a-tetralone,... 

Cyanogen, 32, 31 Cyanogen iodide, 32, 29 complex with sodium iodide, 32, 31 N-Cyanoguanidine, 36, 69 Cyanohydrin formation, 33, 7 3-Cyano-6-isobutyl-2(l)-pyridone,... 

Numerous papers have been devoted to the synthesis of various derivatives of 2-pyridone, 4-pyridone, and aminopyridines based on enamines, di-enamines, dienediamines, and related compounds. For example, enamin-odiketones (153) can react with cyanoacetamide in tetrahydrofuran in the presence of sodium hydride with the formation of a substituted 3-cyano-2-... 

A procedure for the synthesis of 3-cyano-6-methyl-2(l)-pyridone (3) requires isolation of the sodio derivative of formylacetone, (1), and this was accomplished by stirring a suspension of sodium methoxide in ether with ice cooling, dropping in a mixture of acetone and ethyl formate, and removing the ether at a temperature below 70°. The solid residue was treated with an aqueous solution of cyanoacetamide (Eastman) and piperidine acetate and the solution was refluxed, for 2 hrs. After... 

A nucleophile-induced ring transformation reaction of 2-pyranones was reported (Scheme 6) to result in a regioselective synthesis of 2-aminopyridines 21 or 2-pyridones 22 <05SL623>. Urea was used to generate ammonia as a nucleophile source. The reaetion of 23 (R=CN) was initially examined under elevated temperatures and solvent-free conditions. This system yielded a mixture of both 21 and the pyridone equivalent of 23, in equal amounts. The reaction conditions were modified to yield 2-aminopyridine 21 selectively as shown in Scheme 6. However, the only reaction found to be selective for 2-pyridone 22 formation is where the cyano group was replaced with an ester, shown in Scheme 6. Compound 24 was converted to pyridone 22 in good yield. 

Ultraviolet irradiation of pyridines can prodnce highly strained species that can lead to isomerised pyridines or can be trapped. The three picolines and the three cyano-substituted pyridines constitute photochemical triads irradiation of any isomer, in the vaponr phase at 254 nm, results in the formation of all three isomers. From pyridines and from 2-pyridones 2-azabicyclo[2.2.0]-hexadienes and -hexenones can be obtained in the case of pyridines these are nsnally nnstable and revert thermally to the aromatic heterocycle. Pyridone-derived bicycles are relatively stable, 4-alkoxy- and -acyloxy-pyridones are converted in particnlarly good yields. Irradiation of iV-methyl-2-pyridone in aqueous solution prodnces a mixture of regio- and stereoisomeric 4n pins 4n photo-dimers. ... 

There have been several reports of the use of cyano-acetamides as C-C-N synthons in pyridone synthesis. The C-C-C component that is required for the formation of a six-membered ring may be either an 0 /3-unsaturated carbonyl compound or a dicarbonyl compound. Alternatively, pyridones have been formed by base-promoted cyclocondensation of cyano-acetamides with a-keto-ketene 5,A -acetals (Scheme 10). ... 

Diethyl glutaconate and two moles of A -benzylidenemethylamine (XII-95, R = CH3) or benzylideneaniline (XII-9S, R = CgHs) in xylene condense to give compounds characterized as l-substituted-3-benzylidene-S-carbethoxy-2-oxo-6-phenyl-A -piperidenes (interpretation of NMR), which form l-substituted-3-benzyl-5-carboxy-6-phenyl-2-pyridones after heating in methanolic potassium hydroxide. The carboxypyridones have been decarboxylated to Xn-96. Q -Cyano-j3-methylcinnamide and ethyl formate are cyclized in the presence of sodium hydride to 3-cyano4-phenyl-2-pyridone (XII-97). ... 

Succinic acid is incorporated into the 2-, 3- and 7-carbon atoms of ricinine (3-cyano-4-methoxy-l-methyl-2-pyridone). Carbon 1 of succinic acid becomes the nitrUe carbon of ricinine. " Nicotinic acid and nicotinamide are highly incorporated into ricinine, which suggests that these two compounds are closer to ricinine than is succinic acid. Ricinine and nicotine show labeling patterns that are consistent with a pathway where succinic acid or a related dicarboxylic acid is a precursor to nicotinic acid, which is an intermediate in the formation of nicotine and ricinine. The a-carbon of lysine is incorporated into carbon 6 of ricinine and the e-carbon of a-aminoadipic acid is incorporated into carbons 2 and b. " ... 

Cyano-4-methoxy-l-methyl-2-pyridone, see also Recinidine, 855 Cyanmethoxypyridines, from nitropyrldines, 292 a-Cyano-S-methylcinnamide, cyclization with ethyl formate, 616... 

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