Conformational preferences of 3-(dimethylazinoyl) propanoic acid as a function of pH and solvent; intermolecular versus intramolecular hydrogen bonding

RA Nkansah, Y Liu, OJ Alley, JB Gerken…

Index: Nkansah, Richard A.; Gerken, James B.; Roberts, John D. Journal of Organic Chemistry, 2007 , vol. 72, # 18 p. 6956 - 6960

Full Text: HTML

Citation Number: 3

Abstract

The conformational equilibrium of 3-(dimethylazinoyl) propanoic acid (DMAPA, azinoyl= N+ (O−) has a weak pH-dependence in D2O, with a slight preference for trans in alkaline solutions. The acid ionization constants of the protonated amine oxide and carboxylic functional groups as determined by NMR spectroscopy were 7.9× 10− 4 and 6.3× 10− 6, respectively. The corresponding value of K 1/K 2 of 1.3× 102 is not deemed large enough ...