iodine cloride in chloroform 6 h; RefluxInert atmosphere;

in chloroform (Ar); stirring mixt. of boronic acid deriv., 1.1 equiv. of ICl and CHCl3at reflux for 6 h; concg., addn. of diethyl ether, addn. of aq. Na2S2O3, separating organicphase, evapn., filtration, washing with CHCl3, elem. anal.;