2-Pyridones 3-cyano

A third synthesis which has resulted in the preparation of rieinine and a number of its derivatives is due to Schroeter, Seidler, Sulzbacher and Kanitz,i2 who foimd that cyanoacetyl chloride polymerises spontaneously to 6-chloro-2 4-dihydroxy-3-cyano-pyridine. The di-sodium derivative of this with methyl sulphate produces A -methyl-6-chloro-4-hydroxy-3-cyano-2-pyridone (6-chlororicininic acid), the mono-sodium derivative of which, with methyl bromide or sulphate, is converted into 6-chlororicinine and the latter is reduced by zinc and sulphuric acid to rieinine. A fourth synthesis, starting from 3-nitro-4-pyridone, is due to Reitmann. ... 

It is known that 3-aminobenzo[6]furan can be prepared from o-cyanophenols and a-halogenocarbonyl compounds with subsequent Thorpe cyclization (73JPR779). The extension of this synthesis to heteroatom substituted benzo[6]furans is straightforward (76JPR313). The reaction of potassium salts of 3-cyano-2-pyridones (e.g. 27) with a-halogenocarbonyl compounds (esters, ketones) yields 2-alkoxy-3-cyanopyridines which can be cyclized in the presence of sodium ethoxide to give 3-aminofuro[2,3-6]pyridines (Scheme 6). 

Enaminoamides with phosphorus trichloride yielded diazaphosphorins (92JPR711) (Scheme 48). Diazaphosphorins were also obtained by treatment of enaminonitriles, enaminoamides, and enaminothioamides with phosphorus pentasulfide in pyridine (96MC191) (Scheme 49). Fused 3-cyano-2-pyridones react with the Lawesson reagent giving phosphorus-containing heterocycles (95MC191) (Scheme 50). 

The influence of a series of alkyl-substituted 3-cyano-2-pyridones (24 R = Me, Et, Pti, Bu1) and (25 n = 1, 2, 3) on the kinetics of the aminolysis in CHCI3 of / -nitrophenyl acetate (27) by butylamine (26) was studied. It was proposed that the pyridone catalysts (present as 1 1 pyridone-amine complexes) form a weakly bound... 

Cyano-2-pyridones can be prepared in a single step using cyanoacetamide and an unsaturated ketone <95TL(36)3307>. 

From 1,3-Dicarbonyl Compounds (or Synthons) and 3-Amino-Enones or -Nitriles Pyridines are formed from the interaction between a 1,3-dicarbonyl compound and a 3-amino-enone or 3-amino-acrylate 3-cyano-2-pyridones result if cyanoacetamide is used instead of an amino-enone. 

Asymmetric fluorine-containing /1-diketones (01IZV643, 94JFC(67)87) on interaction with 2-cyanoacetamide in the presence KF give 3-cyano-2-pyridones in useful yields only with short polyfluoroalkyl chains (CF2H, CF3) the yield of the tetrafluoroethyl derivative was only 20%, and the octafluorobutyl —4% (Scheme 44). 

The variation which makes use of cyanoacetamide as the nitrogen-containing component leads to 3-cyano-2-pyridones, from which the carbonyl group and/or the cyano group can be subsequently removed. 

Infrared spectra were given for ricinine and for several compounds used in the study of the properties of the enzyme. In the spectrum for ricinine the typical C=N stretching band was present at about 2250 cm The cyano group of 3-cyano-2-pyridones was hydrolyzed if position 1 of the 2-pyridone was unsubstituted or substituted with a methyl or ethyl group and position 4 was unsubstituted or substituted with a methoxyl or ethoxyl group. 

Furo-2-pyridones. 1,4-Dimethyl -3- cyano -5-propargyl -6- hydroxy -2-pyridone dissolved in coned. H2SO4, and poured on ice after a few min. 5,6- (2-methyl-furano)-l,4-dimethyl-3-cyano-2-pyridone. Y 70%. F. e. s. J. Reisch, Arch. Pharm. 297, 754 (1964) furo[3,2-c]coumarins s. Arch. Pharm. 299, 457 (1966). 

The dicarbanion of acetoacetaldehyde is alkylated in the y-position to give salts and copper chelates of j3-ketoaldehydes (W-112 R = C6H5CH2, CH3, n-C Hg and n-CgHn), which are converted to 3-cyano-2-pyridones (XII-113 R = CH3, C6H5CH2, -C4H9) by reaction with cyanoacetamide. n-Butylation of the dianion of a-benzylacetoacetaldehyde followed by cyclization with aqueous cyanoacetamide gives 5-benzyl-3-carboxamido-6-n-pentyl-2-pyridone... 

Tetraethoxypropane (malonaldehyde diethyl acetal) and cyanoaceta-mide in aqueous triethylamine give 3-cyano-2-pyridone (XII-123, 57%). ... 

Vinyl ketones, ethyl cyanoacetate and atnncaiixin acetate give 4,6-disubsti-tuted 3-cyano-2-pyridones (XU-142) by a reaction path that includes a Michael addition and a dehydrogenation. The intermediate 3,4-dihydro-2-pyridones were not detected. When benzylideneacetophenone was used in benzene, the reaction proceeded by a Knoevenagel condensation and it was possible to isolate the intermediate 3-cyano-5,6-dihydro-4,6-diphenyl-2-pyridone, which was dehydrogenated to MI-142 by boiling in acetone. ... 

Dianions of 4- and 6-alkyl-3-cyano-2-pyridones can be formed from the pyridone by treatment with two equivalents of potassium amide in liquid ammonia and can be alkylated, aroylated, or acylated selectively on the... 

Piperidinium acetate 3 Cyano-2-pyridones from y -ketoacetals s. 17, 830... 

Chavan and Degani [198] reported a green protocol for the synthesis of 4,6-disubstituted-3-cyano-2-pyridones 107 108 from cyanoacetamides and 1,3-dicarbonyl compounds or chalcones using IL xmder solvent-free conditions... 

S.S. Chavan, M.S. Degani, Ionic liquid catalyzed 4,6-disubstituted-3-cyano-2-pyridone synthesis under solvent-free conditions, Catal. Lett. 141 (2011) 1693-1697. 

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