C6H5NCO in not given byproducts: NH(C6H5)CHO;

in hexane byproducts: dimethylamine; Bu3SnH soln. added to stannane soln. (room temp.), stirring (3 h),; remove solv., soln. (hexane), chromatography (hexane and hexane/ether 20:1), remove solv.;