摘要:
This invention relates to a method comprising reacting an amino acid derivative of the following general formula (I); ##STR1## (wherein R.sup.1 represents an amino-protective group; R.sup.0 represents hydrogen or, taken together with R.sup.1, represents an amino-protecting group; R.sup.2 represents a carboxy-protecting group; X represents a leaving group) with a thiol compound of the following general formula (II):R.sup.3 SH (II)(wherein R.sup.3 represents an alkyl group of 1 to 7 carbon atoms, an aryl group of 6 to 10 carbon atoms, or an aralkyl group of 7 to 10 carbon atoms) to give a cysteine derivative of the following general formula (III): ##STR2## (wherein R.sup.0, R.sup.1, R.sup.2, and R.sup.3 are as defined above), wherein the reaction is conducted in the presence of a base and water in an organic reaction solvent.
摘要:
A process for producing optically active cysteine derivatives with high optical purity and good quality which is economically advantageous and is high in productivity even on a commercial scale is provided. A process for producing an optically active cysteine derivative which comprises synthesizing a D-form or L-form optically active cysteine derivative of the general formula (2) shown below (R1 represents an amino-protecting group of the urethane or acyl type, R0 represents a hydrogen atom or, taken together with R1, an amino-protecting group, R2 represents an alkyl, aryl or aralkyl group, R3 represents a univalent organic group and * represents the position of an asymmetric carbon) by reacting the corresponding D-form or L-form optically active amino acid derivative of the general formula (1) shown below with an alcohol of the general formula (3) shown below and a strong acid and/or a thionyl halide and recovering the above cysteine derivative (2) from the reaction mixture, the procedural series from reaction to recovery being carried out under conditions such that the medium contacting the above optically active cysteine derivative (2) is within the range from acidic to weakly basic to thereby recover the above cysteine derivative (2) from the reaction mixture while suppressing the decomposition and racemization thereof.
摘要:
The present invention has for its object to provide a commercially useful, expedient and efficient method for purification and isolation of an N-protected (2S,3R)-1-halo-2-hydroxy-3-amino-4-phenylthiobutane (1) or its enantiomer, which is capable of removing the various contaminants, particularly said byproducts, whereby the problem of instability of the compound (1) or its enantiomer can be overcome and a high product yield can be insured.The present invention relates to a method of purifying and isolating an N-protected (2S,3R)-1-halo-2-hydroxy-3-amino-4-phenylthiobutane (1): ##STR1## (wherein X represents a halogen atom; one of P.sup.1 and P.sup.2 represents a hydrogen atom and the other represents an amino-protecting group, or P.sup.1 and P.sup.2 taken together represents an amino-protecting group) or its enantiomer, which comprises using an aromatic hydrocarbon solvent to remove impurities occurring in said compound (1) or impurities occurring in said enantiomer from said compound (1) containing impurities or its enantiomer containing impurities and isolate said compound (1) or said enantiomer as crystals.
摘要:
To produce an 1-alkoxycarbonyl-3-phenylpropyl derivative having little amount of impurities and good quality by a simple, efficient and highly productive process which comprises catalytically reducing an 1-alkoxycarbonyl-3-oxo-3-phenylpropyl derivative. 1-Alkoxycarbonyl-3-phenyl-propyl derivative is provided and obtained by catalytic redution being carried out in an alcohol or a solvent containing the alcohol in the presence of a strong acid having a concentration of 0.4 to 0.5 N, the amount of the strong acid being at least 3 equivalents based on one equivalent of the 1-alkoxycarbonyl-3-oxo-3-phenylpropyl derivative (1 mole).
摘要:
A process for crystallizing N.sup.2 -((S)-1-ethoxycarbonyl-3-phenylpropyl)-N.sup.6 -trifluoroacetyl-L-lysyl-L-proline using one or a mixture of at least two kinds of compound having the general formula: CR.sup.1 R.sup.2 R.sup.3 R.sup.4 as a crystallizing solvent, optionally with an auxiliary solvent which controls crystallization condition.
摘要:
A process for crystallizing N.sup.2 -((S)-1-ethoxycarbonyl-3-phenylpropyl)-N.sup.6 -trifluoroacetyl-L-lysyl-L-proline using one or a mixture of at least two kinds of compound having the general formula: CR.sup.1 R.sup.2 R.sup.3 R.sup.4 as a crystallizing solvent, optionally with an auxiliary solvent which controls crystallization condition.
摘要:
A process for purifying N2-(1(S)-ethoxycarbonyl-3-phenylpropyl)-N6-trifluoroacetyl-L-lysine which comprises subjecting N2-(1(S)-ethoxycarbonyl-3-phenylpropyl)-N6-trifluoroacetyl-L-lysine contaminated with impurities to crystallization from a solvent comprising a water-soluble non-protic organic solvent, thereby removing the impurities into the mother liquor and giving crystals of N2-(1(S)-ethoxycarbonyl-3-phenylpropyl)-N6-trifluoroacetyl-L-lysine, according to which N2-(1(S)-ethoxycarbonyl-3-phenylpropyl)-N6-trifluoroacetyl-L-lysine having a high quality can be obtained in a high yield and a high productivity and which is suitable for practice on an industrial scale.
摘要:
The present invention provides a process for producing 1,2-epoxy-3-amino-4-phenylbutane derivatives which comprises treating a 1-halo-2-hydroxy-3-amino-4-phenylbutane derivative with a base in an aprotic polar organic solvent or a mixed solvent composed of an aprotic polar organic solvent and water and then causing the resulting epoxide to crystallize out from a mixed solvent composed of an aprotic polar organic solvent and water.
摘要:
Processes for efficiently producing .alpha.-halo ketones, .alpha.-halohydrins and epoxides on an industrial scale. The prosesses include one for producing an .alpha.-halo ketone of general formula (3) by decarboxylating a product of reaction between a carboxilic acid derivative of general formula (1) and a metal enolate prepared from an .alpha.-haloacetic acid of general formula (2) or an acceptable salt thereof, one for producing an by reducing the .alpha.-halo ketone (3), and one for producing an epoxide (13) by treating the .alpha.-halohydrin (11) with a base to effect ring closure. The above prosesses are particularly suitable for producing optically active .alpha.-halo ketones, .alpha.-halohydrins and epoxides from the corresponding .alpha.-amino acid derivatives. ##STR1##
摘要:
A main CPU and a sub CPU take share of executing a tone generating process to generate multiple tone signals on a real-time basis without using an exclusive tone generator. The main CPU and sub CPU are formed on a one-chip LSI, thus facilitating realization of a compact electronic musical instrument. According to another structure, the main CPU executes tone generation while the sub CPU performs an effect process, thereby permitting a one-chip LSI to generate an effect-added musical tone.