Method for crystallization of azetidinonecarboxylic acid
View Patent ↗The present invention relates to a method for crystallization of (2R)-2-{(3S,4S)-3-[(1R)-1-(tert-butyldimethylsilyloxy)ethyl]-2-oxoazetidin-4-yl}propionic acid, and is characterized in that crystallization is carried out by mixing a solution containing the compound with a substituted aromatic hydrocarbon solvent and/or a halogenated hydrocarbon solvent. The method can provide a crystal of the compound with a high purity and a high yield while the content of 2S isomer is kept at a low level.
1. A method for crystallizing a compound represented by the formula (1),
comprising a step of mixing a solution prepared by dissolving (2R)-2-{(3S,4S)-3-[(1R)-1-(tert-butyldimethylsilyloxy)ethyl]-2-oxoazetidin-4-yl}propionic acid represented by the following formula (1):
in a first solvent, with a second solvent which is a solvent consisting essentially of substituted aromatic hydrocarbons and/or a solvent consisting essentially of halogenated hydrocarbons to crystallize the compound of formula (1),
with the proviso that the method is carried out without adding an acid.
2. The method according to claim 1 , wherein concentration is carried out during and/or after mixing the solution of the compound represented by the formula (1) with the second solvent.
3. The method according to claim 1 , wherein a ratio of a total weight of the second solvent to the total weight of the first and second solvents is ½ or higher .
4. The method according to claim 1 , wherein a temperature of the mixture of the solution of the compound represented by the formula (1) and the second solvent is 50° C. or lower when the crystallization is carried out.
5. The method according to claim 1 , wherein the solution of the compound represented by the formula (1) contains an ester or ketone.
6. The method according to claim 1 , wherein the solution of the compound represented by the formula (1) contains water.
7. The method according to claim 1 , wherein the solution of the compound represented by the formula (1) has a concentration of the compound represented by the formula (1) of 1% by weight or higher.
8. The method according to claim 1 , wherein the halogenated hydrocarbon solvent is a non-ring halogenated hydrocarbon.
9. The method according to claim 2 , wherein a ratio of a total weight of the second solvent to the total weight of the first and second solvents after carrying out the concentration is ½ or higher.