The basicities of aliphatic amides

Abstract

We report pKa values in aqueous solution at 298 K of the protonated forms of several aliphatic amides, viz., acetamide (pKa = -0.62 ± 0.07), N -methylacetamide (-0.42 ± 0.03), N,N -dimethyl-acetamide (-0.28 ± 0.03), N,N -dimethylformamide (-1.2 + 0.5), urea (0.053 ± 0.002) and thiourea (-0.9 ± :O.l). pKa values are also reported for protonated acetamide and urea in aqueous solution in the temperature range 5-40ºC and in D2O. A previously described conductimetric method was used for all measurements.