Pyridine-3-carboxylic acid amides nicotinamide

Dehydration of pyridine-3-carboxylic acid amide (Nicotinamide) Dehydration of nicotinamide was carried out at different temperatures using conditions similar to those employed for benzamide. The results are shown in Fig.4. The reaction followed zero order kinetics and rate of reaction is very comparable to that of dehydration of benzamide. The kinetic constants are given in Table 2. In contrast with benzamide dehydration of nicotinamide in the absence of catalyst was negligible. 

CeHeONz Pyridine-3-carboxylic acid amide (nicotinamide)... 

Nicotinic acid (3-pyridine carboxylic acid or niacin) nicotinamide (nicotinic acid amide), niacinamide, 3-pyridine-carboxylic acid amide Thiamines, hydroxy-ethylthiamine... 

The involvement of zinc in nicotinamide-based hydride-transfer reactions has led to numerous studies of Group IIB complexes of pyridine carboxylic acid derivatives. Cadmium complexes of 2-pyridinecarboxylic acid, 5 3-pyridinecarboxylic add497 and 3-pyridinecarboxamide498 have been reported. The crystal structure of [Cd(HC02)2L2(H20)2] (L = 3-pyridinecarboxamide) has also been described the metal is in an octahedral environment in which the amide acts as a monodentate N donor.498... 

The name niacin is often used for two compounds, namely pyridine-3-carboxylic acid and pyridine-3-carboxylic acid amide. This confusion occurs because there is no consistency in the empirical nomenclature used in nutrition literature. Harris 1 lists niacin and niacinamide as the terms preferred in the United States, and nicotinic acid and nicotinic acid amide in the British literature. A convenient solution to the problem would be to use the term niacin to refer generically to the two compounds of nutritional significance as anti-pellagra factor and adopt the names nicotinic acid and nicotinamide to refer specifically to each. Nicotinamide has been adopted by the Commission for the Reform of Nomenclature in Biological Chemistry of the International Union of Pure and Applied Chemistry, and nicotinic acid is already in current use in most British, United States and other scientific literature in English. 

Nicotinamide, C HgONg, Mol. Wt. 1221, is pyridine-3-carboxylic acid amide and is determined by hydrolysis with sodium hydroxide, distilling the ammonia formed into standard hydrochloric acid. It is not necessary to perform the preliminary boiling given in the B,P. assay it is easily hydrolysed and a direct distillation can be used. 1 ml O IN = 0-01221 g. 

The amides and hydrazides of pyridine-carboxylic acids arc of some importance, though their chemistry is not marked by unusual properties. Nicotinamide is, of course, an important compound, and isonicotinic acid hydrazide (isoniazid) is an antitubercular drug. Substituted derivatives are used as antidepressants. In general, however, these compounds show normal chemical behaviour. The amides undergo hydrolysis, dehydration and Hofmann bromination without difficulty. Their reduction has been much studied as a route to pyridine aldehydes. The Sonn-Muller reduction is not very satisfactory in this series, but the McFadyen-Stevens reaction is useful . Nicotinic acid diethylamide gives only poor yields of the aldehyde upon reduction with lithium aluminium hydride, but yields from the methyl-phenylamide are high. Most satisfactory is the reduction of nicotinic acid dimethylamide with lithium diethoxyaluminium hydride . 

The carboxylic acid is well known to form stronger hydrogen bonds than the -NH2 moiety on the amide, and the best donor clearly displays a strong preference for the pyridine moiety, the best acceptor site. Once these functionalities have found each other via an acid py synthon, it is left to the amide to interact with itself (typically across an inversion center) via a classic homomeric amide amide dimer. In order to determine whether these structures are representative of cocrystals of acids and nicotinamide, we performed an additional analysis of all relevant data found in the Cambridge Stmctural Database [47]. The search, which included all nicotinamide and iso-nicotinamide co-crystals with carboxylic acids, but excluded other potentially competing moieties such as -OH, yielded 32 hits. In every single case, the pyridine - carboxylic acid synthon was present, which emphasizes that these intermolecular interactimis are very selective, remarkably reliable, and robust, despite the fact that we are dealing with readily reversible non-covalent interactions. The consistency of the motifs can be explained in the context of best donor-best acceptor scenario underpinned by electrostatic considerations. 

Sodium cyanoborohydride (10) produces mainly 1,4-dihydropyridines (11) in the reduction of 3,5-di-cyano- and 3,5-diethoxycarbonyl-pyridines, diborane produces more of the 1,2-isomer. With NBH, mixtures of 1,2- and 1,4-dihydro adducts are produced, the latter predominating when carried out in pyridine solution. Nicotinamide (13) in ethanol can be reduced to (8) in moderate yield at 140 C in diglyme the tetrahydropyridine (8) was isolated in admixture with the piperidine (14), presumably via dehydration of the amide. 3-Nitropyridine affords 3-nitropiperidine in moderate yield when reduced in ethanol. The carboxylic acid and halo derivatives of pyridine are generally not reactive toward NBH. 

Nicotinic acid is pyridine-jff-carboxylic acid (molecular weight 123.1 daltons) and nicotinamide is the corresponding amide (molecular weight 122.1 daltons). Both... 

Another member of the B vitamin complex, nicotinamide is the amide derivative of nicotinic acid (pyridine 3-carboxylic acid) and is the form in which it functions in the... 

Nicotinic acid and nicotinamide are pyridine-3-carboxylic acid and its amide respectively their structural formulas are ... 

The next study focuses on three commonly occurring hydrogen-bonding moieties -carboxylic acid, primary amide, and pyridine - to establish the preference of hydrogen bonding interactions between them. The molecule of choice for this study was iso-nicotinamide which contains the two latter hydrogen bonding moieties. A co-crystallization of iso-nicotinamide with carboxylic acids can in principle result in the three possible heterosynthons shown in Scheme 6. 

Pyridine nucleotides are intimately associated with niacin, another B vitamin (the pellagra-preventive factor). Niacin is a simple pyridine derivative, pyridine-3-carboxylic acid or nicotinic acid. The amide (niacinamide, nicotinamide) also prevents pellagra. The vitamin appears in the coenzyme in this form ... 

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