Reference

Protonation of trimipramine salts of maleate, mesylate and hydrochloride observed by 1H, 13C and 15N NMR spectroscopy

Protonation of trimipramine salts of maleate, mesylate and hydrochloride observed by 1H, 13C and 15N NMR spectroscopy. Somashekar, B. S.; Gowda, G. A. Nagana; Ramesha, A. R.; Khetrapal, C. L. (Centre of Biomedical Magnetic Resonance, Sanjay Gandhi Post-graduate Institute of Medical Sciences, Lucknow 226 014, India). Magnetic Resonance in Chemistry, 43(2), 166-170 (English) 2005 John Wiley & Sons Ltd. CODEN: MRCHEG. ISSN: 0749-1581. DOCUMENT TYPE: Journal CA Section: 63 (Pharmaceuticals) Section cross-reference(s): 22, 27 Protonation of the tricyclic antidepressant drug trimipramine with maleic acid, methanesulfonic acid and hydrochloric acid was studied using 1H, 13C and 15N NMR spectroscopy at natural abundance. The effect of counter ions on the protonation was compared under identical conditions of solvent, concn. and temp. using homonuclear and heteronuclear one- and two-dimensional expts. Differential protonation of the terminal tertiary amine nitrogen is detd. from the indirect spin-spin couplings, chem. shifts, 13C relaxation data and variable-temp. expts. 25332-13-2 is the cas registry number. This chemical is also mentioned in this article. In the maleate salt, only one of the acidic protons is involved in protonation, the other being assocd. with the anion moiety. 15N chem. shifts of the protonated nitrogens are nearly linearly related to the pKa of the constituent acid. .