Acta Pharmaceutica, Vol. 56 No. 2, 2006.
Short communication, Note
Esterification of 7-theophyllineacetic acid with diethylene glycol monomethyl ether
BOIKA TSVETKOVA
JASMINA TENCHEVA
PLAMEN PEIKOV
Abstract
The kinetics of еsterification of 7-theophyllineacetic acid with diethylene glycol monomethyl ether in the presence of dicyclohexylcarbodiimide and 4-dimethylaminopyridine as catalyst was studied. According to the known mechanism, besides the main process, the side-reaction of intramolecular rearrangement with formation of pharmacologically active N-acylurea occurs. The course of the main and the side-process was monitored by RP-HPLC with UV-detection. For that purpose, quantification of both ester and N-acylurea in the reaction mixture was performed. Influence of the concentration of the reactants (acid, alcohol and catalyst) on the progress of esterification and preparation of the by-product was investigated. Based on the obtained results, the reaction conditions leading to maximal yield of the ester and N-acylurea are proposed. Possibility of turning esterification to the synthesis of the side-product was also found. Reactions of the preparation of both the ester and N-acylurea were found to follow first-order kinetics. The rate constants of both processes were estimated.
Keywords
7-theophyllineacetic acid ester; N-acylurea; dicyclohexylcarbodiimide; 4-dimethylaminopyridine; esterification; kinetics
Hrčak ID:
4560
URI
Publication date:
1.6.2006.
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