phosphorus tribromide in dichloromethane 2 h; Heating; Yield given. Yields of byproduct given. Title compound not separated from byproducts;

trimethyl-oxonium tetrafluoroborate; phosphorus tribromide 1) dichloromethan, reflux, 2 h, 2) chloroform 25 deg C, 2 h; Yield given. Multistep reaction;

phosphorus tribromide 1) dichloromethan, reflux, 2 h, 2) benzene, ether, 0 deg C, 30 min; Yield given. Multistep reaction. Yields of byproduct given. Title compound not separated from byproducts;