Preparation of 5-oxo-5,6,7,8-tetrahydro-4H-benzo-[b]-pyran derivatives in ionic liquids

A novel preparation of 5-oxo-5,6,7,8-tetrahydro-4H-benzo-[b]-pyran derivatives promoted by InCl3 center dot 4H(2)O/TMSCI in ionic liquid ([bmin]BF4) is described. The preparative procedure presented in this paper is operationally simple and environmentally friendly. The reaction media and catalyst used can be recovered and reused for at least four times without loss in the catalytic activity. This method is promising for a mass-production process.