Question

how is phosgene prepared

Answer 1

Phosgene is the chemical compound with the formula COCl2. A colorless gas, in low concentrations its odor resembles freshly cut hay or grass.[6] Phosgene is a valued industrial reagent and building block in synthesis of pharmaceuticals and other organic compounds

Answer 2

phosgene is produced by passing purified carbon monoxide and chlorine gas through a bed of porous activated carbon, which serves as a catalyst: ... Because of safety issues,phosgene is often produced and consumed within the same plant, and extraordinary measures are made to contain it.