Skraup Synthesis

Skraup quinoline synthesis is an example for the reaction which involves aldehyde as alkylating agent. The process with aldehydes and ketones is useful when the reaction is intramolecular and stereochemically controlled.

Mechanism

Aromatic compounds whose reactivity is comparable with or greater than that of benzene can be successfully alkylated.

5.2.3 Vilsmeier-Haack Reaction

Reaction of secondary amines with formic acid gives N-formylamines which formylate aromatic compounds in the presence of phosphorus oxyhalide.