Preparation of benzene phosphonate derivatives using multicomponent reaction of phosphites

An effective one-pot synthesis of phosphonate derivatives using dielz-alder reaction of activated acetylenes with phosphoryl-2-oxo-2H-pyran is described. In these reactions, phosphoryl-2-oxo-2H-pyran is synthesized via the reaction of dialkyl acetylene dicarboxylates and alkyl bromides in the presence of trialkyl phosphites under solvent-free conditions at 50oC that provided good yields of products.