Method for synthesizing 2-methyl-2-butenenitrile through direct isomerization of alkene-nitrile mixed liquid

The invention discloses a method for synthesizing 2-methyl-2-butenenitrile through direct isomerization of alkene-nitrile mixed liquid. The method is characterized in that isomerization reaction occurs by adding calcium-containing inorganic base to the alkene-nitrile mixed liquid containing 2-methyl-3-butenenitrile and 3-pentenenitrile so as to generate a product containing the 2-methyl-2-butenenitrile. According to the method, the process of purifying the 2M3BN through reduced pressure rectification is omitted, the calcium-containing inorganic base is used as a catalyst and directly isomerizes the alkene-nitrile mixed liquid containing the 2M3BN and 3PN into the 2M2BN, and the reaction conversion rate and the selectivity are greater than 95% respectively. Compared with a conventional method, the method has the advantages that the rectification separation process of the alkene-nitrile mixed liquid is omitted, so that the whole process route is shortened, the technological process is simplified, the equipment cost and the production cost are reduced, the calcium-containing inorganic base is used as the catalyst, low in price and easy to obtain and can be recycled, and industrial wastewater, waste gases and residues are basically not generated in the whole technological process.