tert.-butyl lithium in hexane; water; pentane

in tetrahydrofuran Grignard compd. from 1,4-dibrombenzene reacts with fluordimesitylborane, boiling for 2 h; solvent removed in vac., addn. of toluene, boiling, hot filtration, recrystn. from n-heptane and n-hexane; elem. anal.;

in not given