Figure 15. Intramolecular effects on basicity of a functional group. Hydrogen bonding in 60 reduces the electron density on the carbonyl oxygen. Resonance effects increase electron density on the carbonyl oxygen in 61

From

It Is Important to Compute Intramolecular Hydrogen Bonding in Drug Design?

María J. R. Yunta

American Journal of Modeling and Optimization. 2017, 5(1), 24-57 doi:10.12691/ajmo-5-1-3