Modified procedure for the synthesis of 2-chloroquinoline-3-carbaldehydes using phosphorus pentachloride

ABSTRACT

An alternative, convenient, and efficient procedure for the synthesis of 2-chloroquinoline-3-carbaldehyde was carried out by the action of Vilsmeier’s reagent on acetanilides using phosphorus pentachloride as chlorinating agent in place of phosphoryl chloride, obtaining good yields for activated acetanilides. The optimal conditions for this reaction requires only 4.5 equivalents of phosphorus pentachloride, 3 equivalents of N,N-dimethylformamide, and 1 equivalent of the corresponding acetanilide at 100 °C for approximately 4 h.

GRAPHICAL ABSTRACT

KEYWORDS:

• Acetanilides
• 2-chloroquinoline-3-carbaldehydes
• cyclization
• phosphorus pentachloride
• Vilsmeier’s reagent

Acknowledgments

The author thanks TSU Noelany Ciguela (Universidad Simón Bolívar, Caracas) and Jaime Charris (Universidad Central de Venezuela, Caracas) for the spectroscopic facilities.