oxygen byproducts: HCl;

Sequentially condensing Cl4B2C2H4 and BBr3 into a reactor in inert atmosphere, stirring (0°C, 72 h).; Removing of volatiles in vac. at 0°C.;

byproducts: {B2(NCH3)4C2H4}n;

in Petroleum ether byproducts: Me3SiCl; warming B-compd. and hydrazine in petroleum ether to room temp. under N2, pptn.; monitoring by (11)B-NMR, removal of solvent and Me3SiCl, recrystn. from petroleum ether, elem. anal.;

Sequentially condensing Cl4B2C2H4 and BBr3 into a reactor in inert atmosphere, stirring (0°C, 72 h).; Removing of volatiles in vac. at 0°C.;

in pentane byproducts: (CH3)3SnCl; stirring B-compd. and SnMe4 in pentane at -78°C under N2, slow warming to room temp., rapid cooling to -78°C, pptn. of Me3SnCl,; fractionated condensation at -30°C, -78°C and -196°C, condensation at -20°C (5-10 times) to remove Me3SnCl;