hydrogenchloride in diethyl ether byproducts: KCl; Ar atmosphere; addn. of HCl/Et2O soln. to B-compd. in Et2O, (room temp., 15 min), refluxing (5 h); filtration of KCl, partial evapn. (14 Torr), distn. (22-84°C, 0.001 Torr); elem. anal.;