Aromatic amides are important precursors for biologically active compounds and are often considered model objects containing a NHCO group, which is ubiquitous in living organisms. In this work we experimentally studied the fusion and solution thermochemistry, and the crystal and liquid heat capacities of three amides: acetanilide, benzamide, and N-methylbenzamide. From the experimental and literature data obtained, the fusion enthalpies at 298.15 K were derived and their relationship with the solution enthalpies of the crystals in N,N-dimethylformamide was analyzed. From the analysis, the solution enthalpies of quasi-equilibrium liquid amides at 298.15 K and hydrogen bonding enthalpies in the neat liquid were derived. The solution enthalpies of quasi-equilibrium liquid amides at 298.15 K are useful for the further evaluation of the fusion enthalpies of benzamide and acetanilide derivatives at 298.15 K by solution calorimetry.
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