The Mixing Enthalpy Interaction Coefficients of N,N′-Hexamethylenebisacetamide with l-Alanine and l-Serine in Aqueous Glucose Solutions at 298.15 K

Abstract

The mixing enthalpies of N,N -hexamethylenebisacetamide (HMBA) with L-alanine and L-serine in aqueous glucose solutions have been determined by using mixingflow isothermal microcalorimetry along with their dilution enthalpies at the temperature of 298.15 K. These results can be used to obtain the heterotactic enthalpic interaction coefficients (h xy , h xxy , and h xyy ) in the range of the glucose molality, (0 to 1.5) mol·kg −1 , according to the McMillan-Mayer theory. Combining our previous research results for glycine (see Liu et al. in J. Chem. Eng. Data 55, 5258-5263, 2010), we find that the heterotactic enthalpic pairwise interaction coefficients h xy between HMBA and the investigated amino acids in aqueous glucose solutions are all positive and reach maximum values at about 0.3 mol·kg −1 glucose. In addition, the order for the value of h xy of the three amino acids in pure water and aqueous solution of the same glucose molality is h xy (L-alanine) > h xy (L-serine) > h xy (glycine). All variations of the heterotactic enthalpic pairwise interaction coefficients with the molalities of glucose in the quaternary systems are discussed in terms of solute-solute and solute-solvent interactions.

Simultaneous determination of enthalpies of dilution and dissociation of protocatechuic acid in aqueous salt solutions by calorimetric measurements

“…The difference between the flow rates measured before and after a complete dilution experiment was less than 0.1%. More detailed information about the experimental procedure was reported elsewhere [27][28][29].…”

Amide exchange reaction: a simple and efficient CuO catalyst for diacetamide synthesis

“…In recent years, the amide exchange reaction (AER) has been used increasingly to synthesize DAPs by pharmaceutical companies and in research laboratories. 6,7 Among the many different DAPs, hexamethylenebisacetamide (HMBA) [8][9][10] is a major anti-carcinogen and medical-chemical intermediate used in the synthesis of different organic chemicals, [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] including hexamethylenetertamine (HMTA), diethyl hexamethylenedicarbamate (EHDC), and diphenyl hexamethylenedicarbamate (PHDC), (Fig. 1).…”