Study On Preparation, Determination And Application Of Triphosgene

Bis(trichIoromethyl)Carbonate (BTC), also named Triphosgene , is now widely accepted that triphosgene can replace phosgene in most cases. As a synthetic auxiliary in the preparation of many important classes of organic compounds has been investigated intensively in last ten years.In this paper a new method to prepare the triphosgene basing on the solventless photochlorination by using initiator and light chlorination was studied.Chlorine gas and dimethyl carbonate as the main raw materials has been proposed. During the preparation highly active initiator and light quantum were chosen to make the chlorination processed quickly and deeping in the manner of chain reaction. The influence of the reaction conditions on photochemical chlorination of dimethyl carbonate was investigated.The experimental results show the best technical conditions is the light quantum is 375w, the temperature is 40~60 , the amount of initiator is 0.2% by using DTBP. This method is safe, convenient and environmentally friendly.A method to analyze the quantitative triphosgene by Fourier Transform Infrared Spectrometry is reported. The result shows linear relation between the concentration of triphosgene and absorbance kept very well. Recover test performed by standard addition method achieved an average value of 98.83%, with RSD of 1.47%.A series of isocyanates and anhydride were synthesized by using triphosgene. In comparison with the phosgene method, the triphosgene method has such advantages as operationally safe and convenient, environmentally friendly, product yield and purity high, and economical.