Kaneka Corporation

Keita Nishino

Teruyoshi Koga

Yasuyoshi Ueda

Masafumi Fukae

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.

Method for crystallization of azetidinonecarboxylic acid

An improved crystallization method for an azetidinone compound represented by the formula 1: 

Crystallization method for intermediates of carbapenem antibiotics

The present invention provides a novel intermediate represented by formula (1), (3), or (4) for efficiently producing a 1&#x3b2;-methylcarbapenem compound for oral administration, and a process for producing the intermediate. That is, the present invention provides a process for producing a novel &#x3b2;-lactam compound represented by formula (4), the process including allowing a &#x3b2;-lactam compound represented by formula (5) as a starting material to react with a compound represented by formula (6) in the presence of a base to obtain a novel &#x3b2;-lactam compound represented by formula (1), protecting the hydroxyl group, subsequently performing cyclization in the presence of a strong base, allowing the cyclized compound to react with diphenylphosphoryl chloride to obtain a novel &#x3b2;-lactam compound represented by formula (3), and eliminating the protecting group therefrom. The formulae referred to are diagrammed as follows: (In the formulae, Rrepresents a trimethylsilyl group or a triethylsilyl group; Rrepresents an aryl group or a heteroaryl group; Rrepresents an aryl group or a heteroaryl group; Rrepresents an alkyl group having 1 to 10 carbon atoms or a cycloalkyl group having 3 to 10 carbon atoms; and X represents a halogen atom.)

Intermediate for carbapenem compound for oral administration and process for producing the same

The present invention provides a process for efficiently producing a 1&#x3b2;-methylcarbapenem compound for oral administration. The process, which is for producing a 1&#x3b2;-methylcarbapenem compound represented by general formula (2), is characterized by reacting a &#x3b2;-lactam compound represented by general formula (1) as a starting material with a thiol compound (R&#x2014;SH) in the presence of a base and optionally eliminating the protective group R. In the formulae (1) and (2), Rdenotes a hydrogen atom, a trimethylsilyl group or a triethylsilyl group; Rdenotes an alkyl group having 1 to 10 carbon atoms or a cycloalkyl group having 3 to 10 carbon atoms; Rdenotes an organic group; and Rdenotes hydrogen, a trimethylsilyl group or a triethylsilyl group.

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Takasago, Japan

Keita Nishino