Cyano substituted pyridine derivative

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. ... 

Colin H. McAteer was born in London, UK, and obtained B.Sc. (Hons) and Ph.D. degrees from the University of Warwick. In 1984, after postdoctoral fellowships at the University of Illinois, Champaign-Urbana, and Oxford University, UK, he joined British Petroleum PLC at the Sunbury Research Centre, UK. In 1991, he moved to Reilly Industries, Inc., Indianapolis, that in 2006 became Vertellus Specialties Inc. Trained in synthetic, kinetic, and mechanistic inorganic chemistry, his industrial expertise is in catalyzed processes to make transportation fuels, petrochemicals, and specialty chemicals. He has patents in areas including GTL, glycol ethers, pyridine derivatives, and ionic liquids. His ongoing research interests include the catalyzed synthesis of pyridine bases and their alkenyl and cyano derivatives, as well as the use of isotope substitution to investigate the mechanism of catalyzed processes. 

Reissert compounds have been prepared from compounds (21) and (23) using either trimethylsilyl cyanide or potassium cyanide as the cyanating agents. Yields ranged from 57% to 71 % <84JHCl 119, 86JHC545). The N-oxides of some thieno[2,3-6]pyridine derivatives, as shown in Equation (8), have been used in the Reissert-Henze reaction to produce cyano-substituted products <83JHC213>. 

The results depicted in Scheme 3 reveal that /i-ethoxycarbonyl/acetyl/cyano enamines 55 react with 54 having a /I-carbonyl group in its C-2 substituent to form pyridine derivatives 56a-e, obviously by cyclodehydration of the initial C-2 unit transfer product. But in the reactions of 55 (Z = COOEt) with oxazolidines 27d, c, b only open-chain products 57 (R1 = COOEt, CN, 4-pyridyl) are isolated. This approach offers a convincing advantage of bringing about a myriad of substitutional variations in pyridine 56 and piperylene 57 based targets (Scheme 3). 

The reaction between P-dicarbonyl compounds and cyanoacetamide to form the corresponding 3-substituted pyridines (MI-121). Acetoacetamide and... 

Reaction of compound 37 with bromine in chloroform results in mono-bromination a to the sulfur. Treatment of this brominated derivative with NaBH3CN in AcOH gives a mixture of products resulting from reduction of the C=N double bond and of elimination of HBr. Reaction of 44 with sodium ethoxide results in the ethoxy-substituted derivative 45, whereas reaction with pyridine gives the dehydrobrominated derivative 46. Reaction of either 44 or 46 with sodium cyanide in dimethyl sulfoxide (DMSO) gives the cyano-derivative 47 <1983HCA971> (Scheme 13). 

Pyridine and its derivatives are technically-important fine chemicals. Their isolation from coal tar is decreasing, whereas their manufacture by synthetic methods has increased rapidly. The classical pathways to pyridine have been discussed by Abramovitch (74HC14-1-4). Many of them rely on the reaction of aldehydes or ketones with ammonia in the vapor phase. However, the condensation processes used suffer from unsatisfactory selectivity. Using soluble organocobalt catalysts of the type [YCoL] allows pyridine and a wide range of 2-substituted derivatives to be prepared selectively and in one step from acetylene and the appropriate cyano compound [Eq.(l)]. 

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