Cyclization method of 4-substituted-2-oxazolidone

Abstract

The invention discloses a cyclization method of 4-substituted-2-oxazolidone. The method is implemented through the following steps: (1) acylation: acylating chiral alkamine in a toluene solvent by adopting chloro-formate in the presence of potassium carbonate, so as to obtain chiral alkamine acylate; (2) cyclization: carrying out cyclization reaction through taking PEG-400 as a phase transfer catalyst, thereby obtaining 4-substituted-2-oxazolidone. Compared with the prior art, the cyclization method disclosed by the invention has the advantages that the adopted phase transfer catalyst is low in cost and is free of risk, reacting steps are reduced, the cost is reduced, and the conditions are mild, so that the method is suitable for industrial production.

Description

technical field

[0001] The invention relates to a cyclization method of 4-substituted-2-oxazolidinone, which belongs to the technical field of synthesis of heterocyclic compounds. Background technique

[0002] 4-substituted-2-oxazolidinone belongs to chiral auxiliary agent, which is a new technology of asymmetric synthesis, all of which are enantiomeric compounds. These compounds are temporarily connected to the substrate through covalent bonds. During the reaction process, these chiral auxiliary agents induce desired chirality, and finally these chiral auxiliary agents are broken and recovered.

[0003] Such 4-substituted-2-oxazolidinone compounds are generally formed from chiral amino acids as starting materials through four steps of esterification, reduction, acylation and cyclization. Potassium tert-butoxide with high price and high risk should be used in the cyclization reaction. Therefore, the existing method has the problem of potential safety hazards in industriali...