70results about How to "Avoid harsh reaction conditions" patented technology

The application belongs to the technical field of organic synthesis, and specifically provides a preparation method of Mal-PEG2-CH2COOH, comprising the following steps: S1, reacting AEEA with maleic anhydride to generate an intermediate, wherein the intermediate is (Z)-2-(2-(N-hydroxyethyl)hydroxyethyl)carboxymethyl)maleic acid monoamide; and S2, performing ring closure reaction on the intermediate to generate Mal-PEG2-CH2COOH. According to the preparation method of the embodiment of the application, the open ring-closure step-by-step synthesis strategy is adopted, so that the harsh reaction condition of high temperature and acid is avoided, the preparation cost is reduced, the overall reaction yield is improved, and the three-waste discharge and environmental pollution are reduced.