Abstract: A heat exchanger includes tubes arranged in one direction, and a corrugated fin provided between the tubes. The corrugated fin includes joints joined to the tubes, and fin bodies that connect the joints which are located next to each other along the wave shape. The fin body includes a cut-raised portion that has a shape in which a part of the fin body is cut and raised for promotion of heat transfer. The cut-raised portion includes a cut-raised end on at least one end of the cut-raised portion in the one direction. The cut-raised end has recesses and projections on its surface that increase hydrophilicity of the surface of the cut-raised end.

Abstract: 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.

Abstract: An improved crystallization method for an azetidinone compound represented by the formula 1: , which is extremely useful as a common intermediate for the synthesis of 1?-methylcarbapenem compounds. The present method provides crystals having higher quality and stability than conventional crystals and excellent filterability at the time of recovery; and an azetidinone compound having a low content of impurity, and 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 1?-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.

Abstract: 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.

Abstract: The present invention has its object to provide an easy process for producing (4R,5S,6S)-3-[[(3S,5S)-5-(dimethylaminocarbonyl)-3-pyrrolidinyl]thio]-6-[(1R)-1-hydroxyethyl]-4-methyl-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid, excellent in antimicrobial activity. The present invention relates to a process for continuously producing (4R,5S,6S)-3-[[(3S,5S)-5-(dimethylaminocarbonyl)-3-pyrrolidinyl]thio]-6-[(1R)-1-hydroxyethyl]-4-methyl-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid without isolating/purifying the reaction intermediate.

Abstract: The present invention provides a novel intermediate represented by formula (1), (3), or (4) for efficiently producing a 1?-methylcarbapenem compound for oral administration, and a process for producing the intermediate. That is, the present invention provides a process for producing a novel ?-lactam compound represented by formula (4), the process including allowing a ?-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 ?-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 ?-lactam compound represented by formula (3), and eliminating the protecting group therefrom.

Abstract: The present invention relates to an azetidinone compound extremely useful as a common intermediate for the synthesis of 1?-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 1?-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.

Abstract: The present invention provides a process for efficiently producing a 1?-methylcarbapenem compound for oral administration. The process, which is for producing a 1?-methylcarbapenem compound represented by general formula (2), is characterized by reacting a ?-lactam compound represented by general formula (1) as a starting material with a thiol compound (R3—SH) in the presence of a base and optionally eliminating the protective group R1. In the formulae (1) and (2), R1 denotes a hydrogen atom, a trimethylsilyl group or a triethylsilyl group; R2 denotes an alkyl group having 1 to 10 carbon atoms or a cycloalkyl group having 3 to 10 carbon atoms; R3 denotes an organic group; and R4 denotes hydrogen, a trimethylsilyl group or a triethylsilyl group.

Abstract: The present invention provides a novel intermediate for efficiently producing a 1?-methylcarbapenem compound for oral administration, and a process for producing the intermediate. That is, the present invention provides a process for producing a novel ?-lactam compound represented by general formula (4), the process including allowing a lactam compound represented by general formula (5) as a starting material to react with a compound represented by general formula (6) in the presence of a base to obtain a novel ?-lactam compound represented by general 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 ?-lactam compound represented by general formula (3), and eliminating the protecting group therefrom.

Abstract: The present invention provides a process for efficiently producing a 1?-methylcarbapenem compound for oral administration. The process, which is for producing a 1?-methylcarbapenem compound represented by general formula (2), is characterized by reacting a ?-lactam compound represented by general formula (1) as a starting material with a thiol compound (R3—SH) in the presence of a base and optionally eliminating the protective group R1. In the formulae (1) and (2), R1 denotes a hydrogen atom, a trimethylsilyl group or a triethylsilyl group; R2 denotes an alkyl group having 1 to 10 carbon atoms or a cycloalkyl group having 3 to 10 carbon atoms; R3 denotes an organic group; and R4 denotes hydrogen, a trimethylsilyl group or a triethylsilyl group.