To use: Used for the synthesis of fine chemicals such as chlorformate, isocyanate, polycarbonate and acyl chloride, and the synthesis of aloxicillin, meloxicillin, paracillin, enalapril and antihypertensive drugs; It is an important intermediate in the production of antibiotics and other drugs; For the manufacture of carbamate pesticides, urea herbicides, synthetic herbicides, insecticides, etc.; It is an important raw material for synthetic polyurethane foam plastics. It can replace phosgene for various chemical reactions and is a good substitute for phosgene.