The invention discloses a one-pot method for preparing a crucial intermediate in oseltamivirphosphate synthesizing reaction. The method is characterized in that: 1,3-butadiene and ethyl
propiolic acid ethyl ester are adopted as raw materials,
alcohol and
isocyanate / salt are adopted as main reactants, DBU is adopted as a catalyst, and no
separation process is required before a finished product is obtained, such that the one-pot method is realized. The method mainly comprises steps that: 1, 1,3-butadiene is cooled to a temperature of -78 DEG C; ethyl
propiolic acid ethyl ester and
hydroquinone are added to 1,3-butadiene, and the mixture is stirred for 3 days under a temperature of 110 DEG C; the mixture is subject to
vacuum distillation, such that 1-
ethyl formate-1,4-
diene cyclohexane is obtained; 2, I2 is added to a solution of 1-
ethyl formate-1,4-
diene cyclohexane and AgOCN; the mixture is heated to a temperature of 35-40 DEG C within 4 hours, such that a mixture A is obtained;
alcohol and waterless HCl are added to the mixture A, and the mixture is stirred for 6-8 hours under a temperature of 35-40 DEG C, such that a mixture B is obtained; DBU is added to the mixture B, and the mixture is subject to a reaction over night under a temperature of 35-40 DEG C; the mixture is purified, such that the finished product is obtained; or DBU is added to the mixture A, the mixture is subject to a reaction over night under a temperature of 35-40 DEG C, and the mixture is purified, such that the finished product is obtained. Compared to existing technologies, the method is substantially advantaged in that: initial raw materials are cheap and easy to obtain, the reaction
route is short, the
synthesis period is shortened, the reaction method is improved into a one-pot method, the separation and purification processes are simple, the yield is high, the reaction efficiency is high, and the method has certain potential to be used in large-scaled productions.