Crystallization Method for Intermediates of Carbapenem Antibiotics

Abstract

The present invention relates to an azetidinone compound extremely useful as a common intermediate for the synthesis of 1β-methylcarbapenem compounds. The present invention provides a crystallization method to obtain a crystal which has a higher quality and a higher stability than a conventional crystal and is excellent in filterability at the time of recovering crystal; an azetidinone compound having a low content of impurity; and an azetidinone compound which has a controlled particle size distribution of crystals and improved handleability and stability. The crystallization is carried out by adding a hydrocarbon solvent to a solution in which an azetidinone compound extremely useful as a common intermediate for the synthesis of 1β-methylcarbapenem compounds is dissolved in the presence of a seed crystal in an amount of 200% by weight or less based on the weight of the azetidinone compound. According to the method, the crystal having a high quality and a high stability and excellent filterability at the time of recovering the crystal can be obtained.

Dependencies are inferred from the claim text.