Sodium nicotinate

Reaction of -picoline over degassed Raney nickel was found to give 5,5 -dimethyl-2,2 -bipyridine (5), the structure of which was established by its synthesis from 2-bromo-5-methylpyridine. Oxidation of this dimethyl-2,2 -bipyridine, and similar oxidation of the diethyl-2,2 -bipyridine derived from 3-ethylpyridinc, gave the corresponding dicarboxylic acid and the same acid was produced by the action of degassed Raney nickel on sodium nicotinate (in water) or on ethyl nicotinate. These transformations established the 5,5 -substitution pattern for three 2,2 -bipyridines derived from 3-substituted pyridines but such evidence is not available for the biaryls... 

The present method is that described by Rinderknecht and Ma.3 4 It is equally applicable to a variety of other heterocyclic, aromatic, and aliphatic anhydrides.4,6 Nicotinic anhydride was first prepared by reaction of nicotinoyl chloride with sodium nicotinate,6,7 and more recently by reaction of potassium nico-tinate with oxalyl chloride in anhydrous benzene.2... 

A similar process is involved in finding the hydronium-ion concentration of 0.10 M sodium nicotinate (sodium salt of niacin). In this case, you need to look at the acid-base equilibrium of the nicotinate ion. Let us see how you answer questions of this sort. 

Note also that the equivalence point for the titration curve of nicotinic acid occurs on the basic side. This happens because at the equivalence point the solution is that of the salt, sodium nicotinate, which is basic from the hydrolysis of the nicotinate ion. The optimum choice of indicator would be one that changes color over a range that includes the pH of the equivalence point... 

At the equivalence point, equal molar amounts of nicotinic acid and sodium hydroxide react to give a solution of sodium nicotinate. You first calculate the concentration of nicotinate ion (stoichiometry problem). Then you find the pH of this solution (hydrolysis problem). 

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