摘要:
A process for preparing a 4-acetoxy-3-hydroxyethylazetidin-2-one derivative having the formula (II): ##STR1## wherein R.sup.1 is a protective group for the hydroxyl group, which comprises reactig a .beta.-lactam compound having the formula (I): ##STR2## wherein R.sup.1 is as difined above and R.sup.2, R.sup.3 and R.sup.4 are the same or different and each is a lower alkyl group having 1 to 4 carbon atoms or an aralkyl group, with acetic anhydride in the presence of a base and a catalyst selected from the group consisting of an organic strong acid, a mineral acid, a Lewis acid, a halogenated acyl compound having the formula (IV):R.sup.8 --CO--X (IV)wherein R.sup.8 is an alkyl group, an aralkyl group or phenyl group and X is a halogen atom, a halogenated sulfonyl compound having the formula (V):R.sup.9 --SO.sub.2 --X (V)wherein R.sup.9 is an alkyl group, an aralkyl group or phenyl group and X is a halogen atom, and a compound having the formula (VI):(R.sup.10).sub.4-n --Si(X').sub.n (VI)wherein R.sup.10 is a lower alkyl group having 1 to 6 carbon atoms or phenyl group, X' is a halogen atom or CF.sub.3 SO.sub.2 O group and n is an integer of 1 to 4. According to the present invention, there can be obtained 4-acetoxy-3-hydroxyethylazetidin-2-one derivatives, which are useful intermediates for preparing carbapenem .beta.-lactam antibiotics, in high yield.
摘要:
A process for preparing a 4-acetoxy-3-hydroxyethylazetidin-2-one derivative having the formula (II): ##STR1## wherein R.sup.1 is a protective group for the hydroxyl group, which comprises reacting a .beta.-lactam compound having the formula (I): ##STR2## wherein R.sup.1 is as defined above, and R.sup.2, R.sup.3 and R.sup.4 are a lower alkyl group having 1 to 6 carbon atoms, phenyl group or an aralkyl group, with acetic anhydride in an organic solvent in the presence of a low concentration of a substituted pyridine. According to the present invention, there can be obtained 4-acetoxy-3-hydroxyethylazetidin-2-one derivatives, which are useful intermediates for preparing carbapenem .beta.-lactam antibiotics.
摘要:
The present invention relates to .beta.-lactam compound having the formula (I): ##STR1## wherein R.sup.1 is a trialkylsilyl group, dimethyl-1,1,2-trimethylpropylsilyl group, acetyl group, benzyloxycarbonyl group, O-nitrobenzyloxycarbonyl group, p-nitrobenzyloxycarbonyl group or t-butyl group, R.sup.2, R.sup.3 and R.sup.4 are a member selected from the group consisting of a lower alkyl group having 1 to 6 carbon atoms, phenyl group and an aralkyl group and a process for preparing the compound which comprises reacting enolsilylethers having the formula (III): ##STR2## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are as above, with chlorosulfonylisocyanate and then reducing the obtained product. The .beta.-lactam compound of the present invention is a useful intermediate for preparing carbapenem .beta.-lactam compound.
摘要:
A process for preparing a 4-acetoxy-3-hydroxyethylazetidin-2-one derivative having the formula (II): ##STR1## wherein R.sup.1 is a protective group for the hydroxyl group, which comprises reacting a .beta.-lactam compound having the formula (I): ##STR2## wherein R.sup.1 is as defined above, R.sup.2, R.sup.3 and R.sup.4 are a lower alkyl group having 1 to 6 carbon atoms, phenyl group or an aralkyl group and R is a protective group for N, with acetic anhydride in an organic solvent in the presence of a base, and removing the protective group for N.4-Acetoxy-3-hydroxyethylazetidin-2-one derivatives are useful intermediates for preparing carbapenem .beta.-lactam antibiotics such as thienamycin and penem .alpha.-lactam antibiotics.
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.
摘要:
A process is disclosed wherein an optically active .beta.-mercaptoalkanoic acid represented by formula (I): ##STR1## wherein R.sub.1 is lower alkyl having from 1 to 4 carbon atoms, is prepared by(1) reacting an optically active .beta.-hydroxyalkanoic acid represented by formula (II): ##STR2## wherein R.sub.1 is the same as defined above, with a halogenating reagent to prepare an optically active .beta.-haloalkanoyl halide represented by formula (III): ##STR3## wherein X is halogen and R.sub.1 is the same as defined above; (2) reacting the .beta.-haloalkanoyl halide with water or an aqueous alkaline solution to prepare an optically active .beta.-haloalkanoic acid represented by formula (IV): ##STR4## wherein X and R.sub.1 are each the same as defined above, or a salt thereof, respectively; and(3) reacting the .beta.-haloalkanoic acid or the salt thereof with a reagent capable of converting the halogen into the thiol group, the configuration of the compound (II), (III), and (IV) being retained throughout the process to prepare the compound represented by formula (I). The product of the present invention is useful as an intermediate for preparation of an antihypertensive agent such as N-(3-mercapto-2-D-methylpropanoyl)-L-proline.
摘要:
A process is disclosed wherein an optically active N-mercaptoalkanoylamino acid is prepared by(1) reacting an optically active .beta.-hydroxyalkanoic acid, with a halogenating reagent to prepare an optically active .beta.-haloalkanoyl halide(2) reacting the .beta.-haloalkanoyl halide with an amino acid to produce an optically active N-.beta.-haloalkanoylamino acid and(3) reacting the N-.beta.-haloalkanoylamino acid with a reagent capable of converting the halogen into the thiol group, the configuration of the formulas (II), (III), (IV), (V), and (VI) being retained in all the optically active compounds throughout the process to prepare the compound represented by formula (I). The product of the present invention, for example, N-(3-mercapto-2-D-methylpropanoyl)-L-proline inhibits the enzymatic conversion of angiotensin I into angiotensin II and therefore is useful for relieving angiotensin-related hypertension.
摘要:
An object of the present invention is to provide a safe method of commercially producing optically active aminoalcohol derivatives, which serve as intermediates for the synthesis of medicinal chemicals such as the immunopotentiating anticancer agent bestatin, in a simple and easy manner in high yields and with high levels of selectivity.The present invention consists in a method of producing 3-amino-1-nitro-4-phenyl-2-butanol derivatives of the general formula (1) ##STR1## wherein R.sup.1 and R.sup.2 each independently represents a hydrogen atom or an amino group protecting group, and a method of producing 3-amino-2-hydroxy-4-phenylbutyric acid derivatives derivable therefrom.
摘要:
An object of the present invention is to provide a safe method of commercially producing optically active aminoalcohol derivatives, which serve as intermediates for the synthesis of medicinal chemicals such as the immunopotentiating anticancer agent bestatin, in a simple and easy manner in high yields and with high levels of selectivity.The present invention consists in a method of producing 3-amino-1-nitro-4-phenyl-2-butanol derivatives of the general formula (1) ##STR1## wherein R.sup.1 and R.sup.2 each independently represents a hydrogen atom or an amino group protecting group, and a method of producing 3-amino-2-hydroxy-4-phenylbutyric acid derivatives derivable therefrom.
摘要:
A process for preparing optically active indoline-2-carboxylic acid by an optical resolution, which comprises subjecting a racemic ester of (R,S)-indoline-2-carboxylic acid having the general formula [(R,S)-I] to the action of an enzyme or a microorganism having a stereo-selective esterase activity, which is capable of asymmetrically hydrolyzing the racemic ester [(R,S)-I] to give optically active indoline-2-carboxylic acid having the formula [II*] so as to produce the hydrolysis product, i.e. optically active indoline-2-carboxylic acid [II*] and an unreacted optically active ester of indoline-2-carboxylic acid having the general formula [I*], isolating each optically active form, and further, if necessary, hydrolyzing the obtained optically active ester [I*] to give an optical antipode of the acid [II*].According to the process of the present invention, optically active indoline-2-carboxylic acid with a high optical purity can be prepared in a simple process with a good yield.