| 摘要 |
PURPOSE:To produce phosgene in a high yield by reacting CO and Cl2 in chlorobenzenes in the presence of triphenylphosphine oxide and/or triphenylphosphine dichloride as catalyst. CONSTITUTION:In the presence of the above-mentioned catalyst Cl2 is dissolved in chlorobenzene and/or dichlorobenzene, and by blowing gaseous CO into the soln. COCl2 is formed quantitatively. CO is preferably used in excess of Cl2, and the reaction temp. is usually 0-200 deg.C. The liq. reaction product is taken out of the CO atmosphere, and gaseous COCl2 is separated from the liq. product by making the pressure lower than the reaction pressure or other method. The COCl2-free liq. residue is recycled to the reaction of CO and Cl2, and repeated use of this liq. residue results in little lowering in COCl2 yield. |
