Potential antifertility agents. 3. Substituted dibenzothiophenecarboxylic acids and derivatives

Nucleophilic acyl substitution is an important class of substitution reactions involving a nucleophile and an acyl compound, such as carboxylic acids and their derivatives. In these reactions, the leaving group attached to the acyl group is substituted by a nucleophile. The general mechanism proceeds via two steps.

Thermodynamics of a Redox Reaction
Thermodynamics is the branch of physics dealing with the relationship between heat and other forms of energy. In an electrochemical cell, chemical energy is converted into electrical energy.
Thus, a link can be predicted between cell potential, free energy change, and the equilibrium constant for the reaction. Cell potential can also be measured as the oxidant or the reducing strength, and similar acid-base strength measures are reflected in equilibrium...

Carboxylic acids are the strongest among organic acids, as they readily lose the hydroxyl proton to form a resonance-stabilized carboxylate ion. In comparison, the acid derivatives lack acidic hydrogens directly attached to a functional group. In these compounds, the acidic nature arises from their ability to lose α hydrogens, making them weakly acidic.
The relative acidic strength of the derivatives can be explained based on the extent of resonance stabilization of the conjugate base. The...

Structure of Carboxylic Acid Derivatives
Carboxylic acid derivatives contain an acyl group attached to a heteroatom such as chlorine, oxygen, or nitrogen. The carbonyl carbon and oxygen are both sp2-hybridized with an unhybridized p orbital.
The three sp2 orbitals of the carbonyl carbon form three σ bonds, one each with the carbonyl oxygen, the α carbon, and the heteroatom, whereas the other two sp2 orbitals of the carbonyl oxygen are occupied by the lone pairs. Further, the unhybridized p...

Infrared spectroscopy is primarily used to determine the types of bonds and functional groups. In carboxylic acid derivatives, a typical carbonyl bond absorption is observed around 1650–1850 cm−1. For esters, the absorption is recorded at around 1740 cm−1, while acid halides show the absorption at about 1800 cm−1. Another acid derivative, the acid anhydrides, exhibit two carbonyl absorption around 1760 cm−1 and 1820 cm−1, arising from the symmetrical and...

Few compounds act as strong acids. A far greater number of compounds behave as weak acids and only partially react with water, leaving a large majority of dissolved molecules in their original form and generating a relatively small amount of hydronium ions. Weak acids are commonly encountered in nature, being the substances partly responsible for the tangy taste of citrus fruits, the stinging sensation of insect bites, and the unpleasant smells associated with body odor. A familiar example of a...