Synthesis of 6′-carbamoylmethylthio-5′-cyano-1′,4′-dihydro-3,4′-bipyridine-3′-carboxylic and 6′-carbamoylmethylthio-5′-cyano-1′,4′-dihydro-4,4′-bipyridine-3′-carboxylic esters and investigation of their stability. 2. Esters of 6′-carbamoylmethyl-thio-5′-cyano-1′,4′-dihydro-4,4′-bipyridine-3-carboxylic acids |
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Authors: | H Kažoka A Krauze M Vilums L Černova L Sīle G Duburs |
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Institution: | (1) Latvian Institute of Organic Synthesis, Riga, LV-1006 |
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Abstract: | The stability of solutions of esters of 6′-carbamoylmethylthio-5′-cyano-2′-methyl-1′,4′-dihydro-4,4′-bipyridine-3′-carboxylic
acids was investigated by HPLC. The corresponding esters of 6′-carbamoylmethylthio-5′-cyano-4,4′-bipyridine-3′-carboxylic
acids,esters of 8-cyano-5-methyl-3-oxo-7-(4-pyridyl)-2,3-dihydro-7H-thiazolo-3,2-a]pyridine-6-carboxylic acids, methyl 3-amino-2-carbamoyl-6-methyl-4-(4-pyridyl)-4,7-dihydrothieno2,3-b]pyridine-5-carboxylate,
and methyl 3-amino-2-carbamoyl-6-methyl-4-(4-pyridyl)-thieno2,3-b]pyridine-5-carboxylate were synthesized as standard compounds
(typical impurities). Analysis by HPLC was realized under the conditions of reverse-phase chromatography. It was established
that solutions of the investigated compounds (with mixtures of acetonitrile with phosphate buffer, having pH values of not
less than 3 and not more than 5, as solvents) are stable for one month when the solutions are stored in a place protected
against light. It is also necessary to use chromatographic systems in which the aqueous components have pH 3–5 during determination
of the purity of the esters of 6′-carbamoylmethylthio-5′-cyano-2′-methyl-1′,4′-dihydro-4, 4′-bipyridine-3′-carboxylic acid
by HPLC in order to separate the analyzed sorbates and their typical impurities more completely.
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Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 841–848, June, 2007. |
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Keywords: | 4 4′ -bipyridines 2 3-dihydro-7H-thiazolo[3 2-a]pyridines thieno[2 3-b]pyridines HPLC |
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