Abstract
For the evaluation of stability of the 2-(3,4-dihydro-1H-isoquinoline-2-yl-methyl)-4-methoxy-6-methylpyrrolo[3,4-c]pyridine-1,3-dione (V) in aqueous solutions (pH 0.39–12.2; 303 K, 308 K, 313 K, 318 K, 333 K, 343 K, 353 K, and 363 K) a HPLC-based method [LiChrosorb® RP-8 (250 × 4 mm, 5 µm); acetonitryle and 0.01 M phosphate buffer pH 2 (35:65); 240 nm] was developed. Determining the value of pKa constant (2.8; 5.3; 9.2) and the thermodynamic parameters of the aforementioned reaction, the equation for the log kpH in function of pH has been established. The lipophilicity coefficients of five pyrrolo[3,4-c]pyridine-1,3(2H)-dione were determined by the HPLC method.
The authors wish to acknomledge Prof. H. Śladowska, D. Szkatuła, and A. Sabiniarz, Department of Chemistry of Drugs Wrocław University of Medicine for providing derivatives of pyrrolo[3,4-c]pyridine-1,3(2H)-dione (I–V) for the study. The study was supported by the 2008/09 research funds as a research project No. N N405 178535 (Ministry of Science and Higher Education, Poland).
Notes
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(∗the extrapolated values).