Chloridedimethylformamide

Chloridedimethylformamide, also known as Vilsmeier reagent or Vilsmeier-Haack reagent, is a chemical compound with the formula [(CH3)2N=CHCl]+Cl-. It is an electrophilic reagent commonly used in organic synthesis, particularly for the formylation of aromatic compounds. This process, known as the Vilsmeier-Haack reaction, introduces an aldehyde group (-CHO) onto an aromatic ring.

The Vilsmeier reagent is typically prepared in situ by reacting phosphorus oxychloride (POCl3) with N,N-dimethylformamide (DMF). The reaction generates a reactive iminium cation which acts as the electrophile. The scope of the Vilsmeier-Haack reaction is broad, encompassing activated aromatic systems such as phenols, anilines, and activated heterocycles. It can also be used to formylate electron-rich alkenes and alkynes.

Beyond formylation, chloridedimethylformamide has found applications in the synthesis of other functional groups. For example, it can be used for the chlorination of active methylene compounds and for the conversion of alcohols to alkyl chlorides. The reagent's utility stems from its ability to generate a potent electrophilic species under mild conditions. Careful control of reaction parameters such as temperature and stoichiometry is important to achieve desired outcomes and minimize side reactions.