Cyano pyridine

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. ... 

To the aqueous suspension of the palladized charcoal catalyst thus obtained are added 20.8 kg of 3-cyano-pyridine (96% purity) and then are added 70 liters of a hydrochloric acid solution prepared by diluting 30 liters of 36% HCI with 40 liters of water. This represents approximately 1.75 mols of HCI for each mol of 3-cyano-pyridine. The suspension is maintained at 10° to 15°C and stirred continuously while introducing a current of hydrogen at a pressure of 3 to 5 psi. When absorption of hydrogen ceases and the 3-cyano-pyridine is completely reduced, the reaction mixture is filtered to remove the catalyst. 

Another example of a biocatalytic transformation ousting a chemical one, in a rather simple reaction, is provided by the Lonza nitotinamide process (Fig. 2.34) (Heveling, 1996). In the final step a nitrile hydratase, produced by whole cells of Rh. rhodoccrous, catalyses the hydrolysis of 3-cyano-pyridine to give nitotinamide in very high purity. In contrast, the conventional chemical hydrolysis afforded a product contaminated with nicotinic acid. 

Table 27. Selected examples of correlation between observed and calculated UV transitions (Del Bene and Jaffe). (Other studied compounds include benzene, pyridine, 1,2-diazine, 1,3-diazine, 1,4-diazine, cyclopentadienide ion, pyrazole, imidazole, 2-pyrrole-carboxaldehyde, furfural, benzonitrile, nitrosobenzene, phenol, phenoxide ion, pyridinium ion, 1-hydroxy-pyridinium ion, 2-cyano-pyridine, 3-cyano-pyridine, 4-cyano-pyridine, 2-amino-pyridine, 3-amino-pyridine, 4-amino-pyridine.)...

To the aqueous suspension of the palladized charcoal catalyst thus obtained are added 20.8 kg of 3-cyano-pyridine (96% purity) and then are added 70... 

Dihydropyridines generated from pyridinium salts carrying electron-withdrawing substituents at the 3 position by borohydride reduction are generally resistant to further reduction. The dihydro derivatives of 1-methyl-3-cyanopyridine, 68, 69, and 70, were recovered unchanged when treated with borohydride in water. Only 1,2-dihydro-l-methyl-3-cyano-pyridine (68) was converted to the tetrahydropyridine 71 when trimethyl borate was added to the reaction medium. Diborane/water achieved the same conversion, while added boric acid returned the starting materials. ... 

H. Adolfsson, C. Coperet, J. P. Chiang, A. K. Yudin, Efficient epoxidation of alkenes with aqueous hydrogen peroxide catalyzed by methyltrioxorhenium and 3-cyano-pyridine, J. Org. Chem. 65, 8651-8658 (2000). 

Thiophen Analogues of Quinoline.—Cyclization of (96) by treatment with AICI3 gave 4-amino-5-cyanothieno[2,3-/)]pyridines. 4-(Acylamino)thieno[2,3-f7]-pyridines were obtained from (186). 4-Amino-5-cyanothieno[2,3-Z>]pyridones were synthesized from 2-amino-3-cyanothiophens and ethyl cyanoacetate in the presence of sodium ethoxide. These compounds showed antibacterial activity. Through the reaction of 2-chloro-3-cyano-pyridines with ethyl thioglycollate followed by base-catalysed ring-closure, 3-aminothieno[2,3-6]pyridines were prepared, and these were transformed into various derivatives, including tricyclic systems. ... 

A new class of dienes (22) has been found to undergo cycloaddition with nitriles to give amino-pyridines (23) (Scheme 11). 4-Dimethylaminobuta-l,3-diene-l,l-dicarbonitriles (24), prepared as shown in Scheme 12, have been cyclized, by reaction with ammonia at 150 °C, to the corresponding 2-amino-3-cyano-pyridines (25). ... 

The photoinitiated reactions of 2-bromobenzonitrile and 2-bromo-3-cyano-pyridine with the carbanion of ethyl cyanoacetate afford the substitution product in good yields (90 and 80%, respectively) by an SrnI process. On the other hand, a non-chain radical nucleophilic mechanism is proposed to occur in the almost quantitative substitution of o-Cl, o-Br, and P-O2NQH4X (F, Cl, Br, I) with this anion in... 

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