IMPROVED METHOD FOR THE CRYSTALLIZATION OF INTERMEDIATES OF CARBAPENEM ANTIBIOTICS

摘要

The invention provides a method for crystallization by which azetidinone compounds extremely useful as the common intermediate for the synthesis of 1ß-methylcarbapenem compounds can be obtained as stable crystals which have higher quality than that of conventional ones and are excellent in the filterability in recovery of crystals; azetidinone compounds lowered in the content of impurities; and azetidinone compounds which are controlled in the particle size distribution of crystals and improved in handleability and stability. The method comprises adding a hydrocarbon solvent to a solution of an azetidinone compound extremely useful as the common intermediate for the synthesis of 1ß-methylcarbapenem compounds in the presence of at most 200wt% of seed crystals based on the weight of the azetidinone compound. According to the method, high-quality and stable crystals excellent in the filterability in recovery of crystals can be obtained.