3-Cyano-6-methyl-2-pyridones

The cyclization of the 1,3-enyne amines with cyanacetamide in the presence of bases (55°C, H2O, 2 h) leads to 3-cyano-6-methyl-2-pyridones (155), yield 77% (69ZOR1179). 

Diazomethane reacted with 4-carboxy-3-cyano-6-methyl-2-pyridone (X-140) in the expected manner to form the methyl ester (X-141). Further treatment of X-141 with diazomethane led to a mixture of 0- (X-142) and A -methyl (X-143)... 

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. ... 

Brandt, H., Hbrnle, R. and Leverenz, K. (1982). Color stable modification of monoazo dyestuff—viz butyl cyano methyl nitrophenyl azo pyridone, used for dyeing polyester fibers. Bayer AG Patent DE 3 046 587. [274]... 

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 cycloadducts formed from the Diels-Alder reaction of 3-amino-5-chloro-2(17/)-pyrazinones with methyl acrylate in toluene are subject to two alternative modes of ring transformation yielding either methyl 6-cyano-l,2-dihydro-2-oxo-4-pyridinecarboxylates or the corresponding 3-amino-6-cyano-l,2,5,6-tetrahydro-2-oxo-4-pyridinecarboxylates. From the latter compounds, 3-amino-2-pyridones can be generated through subsequent loss of HCN <96 JOC(61)304>. Synthesis of 3-spirocyclopropane-4-pyridone and furo[2,3-c]pyridine derivatives can be achieved by the thermal rearrangement of nitrone and nitrile oxide cycloadducts of bicyclopropylidene <96JCX (61)1665>. 

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,... 

Note 5) in 400 ml. of water and piperidine acetate (prepared by adding piperidine to 8 ml. of glacial acetic acid in 20 ml. of water until the solution is just basic to litmus). The flask is equipped with a reflux condenser, and the mixture is heated under reflux for 2 hours. At the end of this time 200 ml. of water is added, and the solution is acidified (to litmus) with acetic acid, causing separation of the product as a voluminous yellow precipitate. The mixture is cooled in an ice bath for 2 hours, and the product is collected on a suction filter, washed on the filter with three 100-ml. portions of ice water, and dried (Note 6). The yield of 3-cyano-6-methyl-2(l)-pyridone is 59-67 g. (55-62%) m.p. 292-294° (dec., cor.) (Notes 7, 8, and 9). 

Analysis of the crude product is approximately 0.9% low in carbon. Analytically pure 3-cyano-6-methyl-2(l)-pyridone, m.p. 296.5-298.5° (dec., cor., under nitrogen), can be obtained by one recrystallization from 50% (by volume) ethanol, using 66 ml. per g. of product and treating the hot solution with Darco. Recovery of the product is 60%, and concentration of the mother liquor yields impure material. 

A similar procedure can be used for preparing other 2(l)-pyr-idones. For example, 3-cyano-6-isobutyl-2(l)-pyridone can be obtained from the sodium salt of formylmethyl isobutyl ketone, and 3-cyano-5,6-dimethyl-2(l)-pyridone can be prepared from the sodium salt of a-formylethyl methyl ketone.5... 

The procedure used for preparing the sodium salt of formyl-acetone is a modification of a previously described procedure.2 3-Cyano-6-methyl-2(l)-pyridone has been prepared by the condensation of /3-ethoxycrotonaldehyde diethyl acetal with cyano-acetamide 6 and by condensation of the sodium salt of formyl-acetone with cyanoacetamide.7... 

Cyano-4-trifluoromethyl-6-aryl-2(l//)-pyridones 100 react with hydrazine hydrate to give exclusively 5-trifluoro-methyl-3-arylpyrazoles 101 (Scheme 55) <2002JFC(115)9>. 

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... 

Synthesis of a heteroeycle. An efficient synthesis of 3-cyano-6-methyl-2(lH)-pyridone (3) starts with 3-ketobutyraldehyde 1-dimethylacetal (1), available from Henley and Co. A mixture of 5 moles of (1) and 5.5 moles of cyanoacetamide (2)... 

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