Efficient synthesis of heterophosphole-2-sulfides by solvent-free microwave reaction

Microwave irradiation of a stoichiometric amount of Lawesson’s reagent in the presence of o-aminophenols, o-aminothiophenols, o-phenylenediamines, or catechols leads to benzoxazaphosphole-, benzothiazaphosphole-, benzodiazaphosphole-, and benzodioxaphosphole-2-sulfides, respectively, in good yields in a fast and direct way under solventless conditions. The procedure requires short reaction times and is similar for all reagents; thus it may be used in parallel synthesis.