TY  - JOUR
AU  - Dumanović, Dragica
AU  - Juranić, Ivan O.
AU  - Dželetović, D.
AU  - Vasić, Vesna M.
AU  - Jovanović, J.
PY  - 1997
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/2080
AB  - The prototropic exchange equilibria of two drugs, nizatidine (I) and ranitidine (II); and also of structurally related the N,N-dimethyl-2-nitro-1,1-ethenediamine molecule (III) were investigated. From the changes in electronic spectra in media of various acidity several protonation constants were determined. For nizatidine pK values were -0.82, 1.95, and 6.67; for ranitidine pK values were 1.95 and 8.13; and for III was 2.60. The hydroxylation equilibrium constant in strongly alkaline media was determined too. Corresponding pK(a) values were 13.23 for I, 13.26 for II and 13.76 for III. Molecular orbital calculations of electronic spectra confirmed that pK 1.95 for I and II, and pK 2.60 for III, are associated with C-protonation of nitroethenediamine fragment, while all pK(a) values correspond to the addition of HO- anion at the same double bond. (C) 1997 Elsevier Science B.V.
T2  - Journal of Pharmaceutical and Biomedical Analysis
T1  - Protolytic constants of nizatidine, ranitidine and N,N-dimethyl-2-nitro-1,1-ethenediamine; spectrophotometric and theoretical investigation
VL  - 15
IS  - 11
SP  - 1667
EP  - 1678
DO  - 10.1016/S0731-7085(96)01977-2
ER  - 

@article{
author = "Dumanović, Dragica and Juranić, Ivan O. and Dželetović, D. and Vasić, Vesna M. and Jovanović, J.",
year = "1997",
abstract = "The prototropic exchange equilibria of two drugs, nizatidine (I) and ranitidine (II); and also of structurally related the N,N-dimethyl-2-nitro-1,1-ethenediamine molecule (III) were investigated. From the changes in electronic spectra in media of various acidity several protonation constants were determined. For nizatidine pK values were -0.82, 1.95, and 6.67; for ranitidine pK values were 1.95 and 8.13; and for III was 2.60. The hydroxylation equilibrium constant in strongly alkaline media was determined too. Corresponding pK(a) values were 13.23 for I, 13.26 for II and 13.76 for III. Molecular orbital calculations of electronic spectra confirmed that pK 1.95 for I and II, and pK 2.60 for III, are associated with C-protonation of nitroethenediamine fragment, while all pK(a) values correspond to the addition of HO- anion at the same double bond. (C) 1997 Elsevier Science B.V.",
journal = "Journal of Pharmaceutical and Biomedical Analysis",
title = "Protolytic constants of nizatidine, ranitidine and N,N-dimethyl-2-nitro-1,1-ethenediamine; spectrophotometric and theoretical investigation",
volume = "15",
number = "11",
pages = "1667-1678",
doi = "10.1016/S0731-7085(96)01977-2"
}

Dumanović, D., Juranić, I. O., Dželetović, D., Vasić, V. M.,& Jovanović, J.. (1997). Protolytic constants of nizatidine, ranitidine and N,N-dimethyl-2-nitro-1,1-ethenediamine; spectrophotometric and theoretical investigation. in Journal of Pharmaceutical and Biomedical Analysis, 15(11), 1667-1678.
https://doi.org/10.1016/S0731-7085(96)01977-2

Dumanović D, Juranić IO, Dželetović D, Vasić VM, Jovanović J. Protolytic constants of nizatidine, ranitidine and N,N-dimethyl-2-nitro-1,1-ethenediamine; spectrophotometric and theoretical investigation. in Journal of Pharmaceutical and Biomedical Analysis. 1997;15(11):1667-1678.
doi:10.1016/S0731-7085(96)01977-2 .

Dumanović, Dragica, Juranić, Ivan O., Dželetović, D., Vasić, Vesna M., Jovanović, J., "Protolytic constants of nizatidine, ranitidine and N,N-dimethyl-2-nitro-1,1-ethenediamine; spectrophotometric and theoretical investigation" in Journal of Pharmaceutical and Biomedical Analysis, 15, no. 11 (1997):1667-1678,
https://doi.org/10.1016/S0731-7085(96)01977-2 . .