摘要:
An optically active N-protected azetidine-2-carboxylic acid (5) can be produced by preparing an optically active 4-amino-2-halobutyric acid (3) by halogenating an optically active 3-hydroxy-2-pyrrolidinone (1) with inversion of configuration to prepare an optically active 3-halo-2-pyrrolidinone (2) followed by hydrolysis or by halogenating an optically active 4-amino-2-hydroxybutyric acid ester (6) with inversion of configuration to prepare an optically active 4-amino-2-halobutyric acid ester (7) followed by hydrolysis or by halogenating the compound (6) with inversion of configuration to prepare the compound (7), cyclizing the same to prepare the compound (2) followed by hydrolysis, further cyclizing the compound (3) followed by treating the reaction product with an amino group-protecting agent. The thus-obtained compound (5) can be improved its optical purity further by recrystallization
摘要:
An ultra micro indentation testing apparatus comprises: a lever stand provided with a center lever having a silicon probe and a diamond indenter disposed therein; a moving mechanism for moving the lever stand in a triaxial direction; in indentation mechanism for pushing the diamond indenter in a sample; a displacement gage for measuring a displacement of the silicon probe or the diamond indenter; and an optical picture device for positioning the silicon probe or the diamond indenter and observing the surface of the sample. The apparatus has, in combination, a hardness measuring function based on the measurement of the force and depth of the diamond indenter pushed in the surface of the sample, an atomic force microscopic function of acquiring the shape of the surface of the sample based on a displacement of the diamond indenter or the silicon probe, and an optical microscopic function of observing the surface of the sample by the optical picture device. Furthermore, the testing apparatus is equipped with both the function of measuring the hardness of the surface of material in a ultra micro region and the surface observing function with high accuracy.
摘要:
A testing method is provided for determining the hardness of a micro region, using indentation curves indicating relations between observed penetration depths and indenting forces when an arbitrary shaped indenter is pushed into standard samples of plural types. The method involves (1) measuring relations between observed penetration depths and indenting forces when the arbitrary shaped indenter is pushed into standard samples of plural types, to prepare the indentation curves, (2) determining a reference function indicative of macro hardness, by standardizing the relations between the indenting forces and macro hardness at the same penetration depth as an index, for the indentation curves of the standard samples of plural types, (3) measuring a relation between the penetration depth and indenting force of an arbitrary sample, and (4) determining the hardness of a micro region from the measured value in step (3) according to the reference function as determined in step (2).
摘要:
An industrial advantage process for producing high-purity 3-hydroxytetrahydrofuran easily and simply, which comprises reducing a 4-halo-3-hydroxybutyric acid ester (1) with a boron hydride compound and/or an aluminum hydride compound as a reducing agent in an organic solvent immiscible with water; treating the reaction mixture with an acid and water to thereby effect conversion to the corresponding 4-halo-1,3-butanediol and at the same time giving an aqueous solution containing said compound; carrying out the cyclization reaction of the 4-halo-1,3-butanediol in said aqueous solution; extracting the resulting 3-hydroxytetrahydrofuran from the 3-hydroxytetrahydrofuran-containing aqueous solution using an organic solvent immiscible with water; and isolating the 3-hydroxytetrahydrofuran by concentration and/or distillation of the solution obtained.
摘要:
The present invention provides an economically advantageous and efficient process for producing an optically active homophenylalanine derivative of the general formula (IV), and an intermediate therefor and a process for producing it. The present invention relates to a process for producing homophenylalanine derivative of the general formula (IV) which comprises reacting a .beta.-benzoylacrylic acid derivative of the general formula (II) with a 1-arylethylamine derivative of the general formula (III) and reducing the resultant .gamma.-oxo-homophenylalanine derivative of the general formula (I). ##STR1##
摘要:
The present invention provides a method for easily producing an (R)-3-[4-(trifluoromethyl)phenylamino]-pentanoic acid amide derivative useful for an intermediate for pharmaceutical products, particularly an inhibitor of a cholesteryl ester transfer protein (CETP) from easily available raw materials. In the present invention, (S)-N-[4-(trifluoromethyl)phenyl]-3-hydroxypentanoic acid amide prepared from easily available raw materials leads a production of (R)-4-ethyl-1-[4-(trifluoromethyl)phenyl]-2-azetidinone to give (R)-3-[4-(trifluoromethyl)phenylamino]-pentanoic acid amide. Furthermore, (R)-4-ethyl-1-[4-(trifluoromethyl)phenyl]-2-azetidinone is reacted with a carbamic acid ester to give an (R)-3-[4-(trifluoromethyl)phenylamino]-pentanoic acid amide derivative.
摘要:
A process for preparing an enol silyl ether compound from a diazoacetoacetic acid ester having the general formula (IV): ##STR1## wherein R.sup.1 is a lower alkyl group having 1 to 6 carbon atoms, phenyl group, a substituted phenyl group, an aralkyl group or allyl group, and R.sup.2, R.sup.3 and R.sup.4 are the same or mutually different and each is a lower alkyl group having 1 to 6 carbon atoms, which comprises reacting a diazoacetoacetic acid ester having the general formula (I): ##STR2## wherein R.sup.1 is the same as defined above, with a trialkylsilyl chloride having the general formula (II): ##STR3## wherein R.sup.2, R.sup.3 and R.sup.4 are the same as defined above, in an inert solvent in the presence of an organic base and an alkali halide having the general formula (III):MX (III)wherein M is an alkaline metal and X is bromine atom or iodine atom. The desired compound is useful as an intermediate for synthesis of carbapenem .beta.-lactam antibiotics.