Isonicotinic acid (4-pyridinecarboxylic, γ-pyridinecarboxylic) - an organic compound , heterocyclic monobasic carboxylic acid , a structural isomer of nicotinic acid , exhibits weak anti-vitamin properties (it is PP anti-vitamin ).
| Isonicotinic acid | |
|---|---|
 | |
 | |
| Are common | |
| Systematic name | Pyridine-4-carboxylic acid |
| Traditional names | Isonicotine kilota, Para-pyridinecarboxylic acid, 4-pyridinecarboxylic acid, γ-pyridinecarboxylic acid, anti-vitamin PP |
| Chem. formula | C 6 H 5 NO 2 |
| Rat formula | C 5 H 4 NCOOH |
| Physical properties | |
| condition | white crystalline solid or colorless crystals, odorless |
| Molar mass | 123.1094 ± 0.006 g / mol |
| Thermal properties | |
| T. melt. | 318-319 ° C |
| Chemical properties | |
| pK a | 4.9 |
| Solubility in water | 0.58 g / 100 ml |
| Classification | |
| Reg. CAS number | 55-22-1 |
| PubChem | |
| Reg. EINECS number | 200-228-2 |
| Smiles | |
| Inchi | |
| Chebi | CHEBI: 6032 |
| ChemSpider | |
| Security | |
| LD 50 | 436 mg / kg (rat, intraperitoneally), 5000 mg / kg (rat, oral). |
| Toxicity | slightly toxic, exhibits the properties of an irritant.  |
Content
Getting
Isonicotinic acid is mainly obtained by oxidation of γ-picoline or γ-ethylpyridine with potassium permanganate solution . The best yield is achieved by the oxidation of trimethylol-γ-picoline, by heating the entire fraction boiling at 140-145 ° C, with an aqueous solution of formaldehyde [1] .
Isonicotinic acid can also be obtained by thermal decomposition of pyridine-2,4,5-tricarboxylic acid.
Physico-chemical properties
It is a solid crystalline substance without color (technical isonicotinic acid has a color from slightly cream to almost yellow), poorly soluble in water (solubility grows when heated), insoluble in ethyl alcohol , acetone and diethyl ether .
With respect to the carboxyl group, it forms a number of derivatives characteristic of carboxylic acids : with metals - salts (isonicotinoates), amide , halides, esters and others.
According to the heterocycle (like pyridine ) it easily enters into the nucleophilic substitution reaction S N.
As a tertiary amine with strong acids ( hydrochloric , sulfuric, etc.), as well as with alkyl halides, it forms quaternary ammonium compounds.
Biological properties
It shows weak anti-vitamin properties (anti-vitamin PP), its derivatives - amide and hydrazide have more pronounced anti-vitamin properties. Replacing the nicotinamide molecule with a more active radical in the structure of the NAD + coenzyme and thereby inhibit the redox reactions that occur in the respiratory chain (these properties are most pronounced for hydrazide ( GINC )) [2] .
It is weakly toxic, has an irritating effect on the skin and mucous membranes ( irritant ).
Application
Isonicotinic acid is used as a raw material for the production of very valuable anti-TB drugs :
- isonicotinic acid hydrazide ( GINC ) and its derivatives (metazide, saluside , phthivazide , etc.);
- thioamide and its derivatives ( ethionamide , protionamide ), similar in action to GINC, but less active.
In the production of antidepressants - iproniazide , nialamide ( MAO inhibitors ).
In the production of herbicides , for example, nicotinic acid phenoxyarylamides.
Notes
- ↑ Dirikhs A., Kubichka R. Phenols and coal bases .. - M. , 1958. - 468 p.
- ↑ Stroev EA. Biological chemistry: Textbook for pharmaceuticals. in-to and pharmaceuticals. Fak. honey. in-com. - M .: Higher school, 1986.- 479 p.
See also
- Isonicotinamide
- A nicotinic acid
- Gink
- Anti-TB drugs