A process for preparing diisocyanate compounds by the i following two-step reaction without using phosgene. In the first step, a diamine and dimethyl carbonate are reacted with each other in the presence of an alkali catalyst to synthesize a corresponding urethane compound and, in the second step, the urethane compound is thermally decomposed in a high-boiling solvent under a reduced pressure of 1 to 700 Torr in the presence of a catalyst composed of a simple substance of metal selected from among manganese, molybdenum, tungsten, zinc, and beryllium or a compound thereof to obtain a corresponding diisocyanate compound.
一种不使用
光气,通过以下两步反应制备二
异氰酸酯化合物的工艺。第一步,二胺和
碳酸二甲酯在碱催化剂存在下相互反应,合成相应的
氨基甲酸乙酯化合物;第二步,
氨基甲酸乙酯化合物在由
锰、
钼、
钨、
锌和
铍中选出的简单
金属物质或其化合物组成的催化剂存在下,在 1 至 700 托的减压条件下,在高沸点溶剂中进行热分解,得到相应的二
异氰酸酯化合物。