aluminium in N,N-dimethyl-formamide byproducts: Al(3+); Electrolysis; electrolysis carried out in a single-compartment cell at room temp., starting materials dissolved in DMF containing KBr or n-Bu4NBr, solvent andexcess B(OCH3)3 evaporated under vacuum, medium hydrolysed at 0° C with an HCl or H2SO4 soln.; extraction with Et2O (3 x 20 ml if the solvent evaporated or 3 x 60 ml otherwise), dried over sodium or magnesium sulfate and concentrated undervacuum, side product phenol formation avoided by work-up under inert at mosphere, recrystallized in CH2Cl2;

molecular sieve in toluene 24 h; Heating;