The invention provides a method for preparing
cefixime, which belongs to the
medicine synthesis technical field and comprises the steps of preparation of 7-AVCA, preparation of
cefixime methyl ester, preparation of the
cefixime and so on. The method aims at the prior amino de-protection to make an improvement, and uses
penicillin acylase to substitute
trifluoroacetic acid and so on in the prior process to ensure that an amino de-protection reaction is greatly improved, the use of organic solvents can be completely avoided, and acylase can also be reused at the same time.
Methylene dichloride and
tetrahydrofuran solvents in the prior process are substituted by adopting
alcohol,
ketone or ester solvents, so that an amidation reaction is greatly improved, which ensures that reaction solvents are easy to recover and reuse, can reduce production cost, reduce the
discharge of waste liquid, reduce the
pollution to the environment, can completely recover a byproduct, namely
mercaptobenzothiazole produced by the reaction, improve the atom
utilization rate of reaction raw-materials, and greatly improve the hydrolyzation and
crystallization of subsequent products and the quality of a finished product.