Nucleophilic substitution reactions are valuable for alkyl halides with sp³ hybridized carbon. These reactions are initiated by nucleophiles, attacking the partially positively charged carbon atom in the haloalkane, resulting in substitution with the departing halide ion.

Nucleophiles are electron-rich species that attack the electron-deficient part of a substrate molecule, leading to nucleophilic substitution reactions. In these reactions, a nucleophile reacts with a haloalkane, replacing the existing nucleophile, and the departing halogen forms a halide ion.

Haloalkanes tend to dissolve in organic solvents because the new intermolecular attractions between haloalkanes and solvent molecules have similar strength to the attractions being broken in separate haloalkane and solvent molecules, leading to higher solubility in organic solvents.

Alkyl bromides are prepared by constant boiling with HBr (48%). This method ensures the synthesis of alkyl bromides in good yields by maintaining a consistent concentration of hydrobromic acid throughout the reaction.

The reactions of primary and secondary alcohols with HCl require the presence of the catalyst ZnCl₂. The catalyst aids in the conversion of alcohols into alkyl halides in the presence of hydrochloric acid.