摘要:
An industrially advantageous method of producing &bgr;-halogeno-&agr;-aminocarboxylic acids is provided. Methods are also provided of producing optically active N-protected-S-phenylcysteines having high optical purity and of intermediates thereof, respectively, in which the above production method is utilized. A method of producing &bgr;-halogeno-&agr;-aminocarboxylic acids or salts thereof is disclosed which comprises halogenating the hydroxyl group of a &bgr;-hydroxy-&agr;-aminocarboxylic acid (in which the basicity of the amino group in &agr;-position is not masked by the presence of a substituent on said amino group) or a salt thereof with an acid with a halogenating agent. A method of producing optically active N-protected-S-phenylcysteines represented by the general formula (3) or salts thereof is further disclosed which comprises applying the above production method to optically active serine or a salt thereof and then carrying out treatment with an amino-protecting agent and reaction with thiophenol under a basic condition.
摘要:
This invention provides a method of isolating N-protected-S-phenylcysteine (1) of high purity, expediently, efficiently and in good yield, which comprises causing said N-protected-S-phenylcysteine to be salted out in the form of a base salt in the presence of water. wherein R1 represents an amino-protecting group; R2 represents a hydrogen atom or, either independently of R1 or taken together with R1, represents an amino-protecting group.
摘要翻译:本发明提供了一种方法,有效和高效分离高纯度N-保护的S-苯基半胱氨酸(1)的方法,其包括使所述N-保护的S-苯基半胱氨酸以碱的形式盐析 盐,其中R 1表示氨基保护基; R 2表示氢原子,或独立地为R 1或与R 1一起表示氨基保护基。
摘要:
A nitrous acid salt is added at a temperature of 10 to 80° C. to an aqueous solution which contains an optically active 2-aminocarboxylic acid (4) and a protonic acid, the amount of the latter acid being 1 to 3 equivalents to the former, and which has a proton concentration of 0.5 to 2 mol/kg to conduct a reaction to thereby produce an optically active 2-hydroxycarboxylic acid (1). Thionyl chloride and a basic compound are caused to act on the compound (1) to chlorinate it and simultaneously invert the configuration in the 2-position. Thus, an optically active 2-chlorocarboxylic acid chloride (5) is induced. The compound (5) is hydrolyzed to induce an optically active 2-chlorocarboxylic acid (2). The compound (2) is reacted with a thioacetic acid salt to incorporate an acetylthio group thereinto and simultaneously invert the configuration in the 2-position to thereby produce an optically active 2-acetylthiocarboxylic acid (3).
摘要:
A nitrous acid salt is added at a temperature of 10 to 80° C. to an aqueous solution which contains an optically active 2-aminocarboxylic acid (4) and a protonic acid, the amount of the latter acid being 1 to 3 equivalents to the former, and which has a proton concentration of 0.5 to 2 mol/kg to conduct a reaction to thereby produce an optically active 2-hydroxycarboxylic acid (1). Thionyl chloride and a basic compound are caused to act on the compound (1) to chlorinate it and simultaneously invert the configuration in the 2-position. Thus, an optically active 2-chlorocarboxylic acid chloride (5) is induced. The compound (5) is hydrolyzed to induce an optically active 2-chlorocarboxylic acid (2). The compound (2) is reacted with a thioacetic acid salt to incorporate an acetylthio group thereinto and simultaneously invert the configuration in the 2-position to thereby produce an optically active 2-acetylthiocarboxylic acid (3).
摘要:
The present invention relates to a process for efficiently producing an optically active 2-bromocarboylic acid and an optically active 2-sulfonyloxycarboxylic acid, which are important in the production of medicinal compounds and so forth. An optically active 2-sulfonyloxycarboxylic acid ester is subjected to deprotection under acid conditions to obtain an optically active 2-sulfonyloxycarboxylic acid. A metal bromide is caused to act on the acid to brominate it with configuration inversion at position 2 to thereby produce an optically active 2-bromocarboxylic acid. The resultant optically active 2-bromocarboxylic acid is isolated/purified by subjecting it to a step in which the acid is crystallized and separated as a salt with a base. Thus, an optically active 2-bromocarboxylic acid having a high chemical purity and high optical purity can be produced.
摘要:
An optically active amino acid derivative is produced by N-protecting an optically active 3-haloalanine derivative followed by cyclization, or cyclizing this derivative followed by N-protection to thereby give an optically active N-protected-aziridine-2-carboxylic acid derivative which is protected by a benzenesulfonyl group substituted by nitro at the 2- and/or 4-positions and then treating this product with an organic metal reagent, or by N-protecting an optically active 3-haloalanine derivative to thereby give N-protected-aziridine-2-carboxylic acid which is protected by a benzenesulfonyl group substituted by nitro at the 2- and/or 4-positions and then treating this product with an organic metal reagent. According to this process, natural and unnatural optically active amino acids can be produced from inexpensive materials by using simple procedures.
摘要:
An optically active amino acid derivative is produced by N-protecting an optically active 3-haloalanine derivative followed by cyclization, or cyclizing this derivative followed by N-protection to thereby give an optically active N-protected-aziridine-2-carboxylic acid derivative which is protected by a benzenesulfonyl group substituted by nitro at the 2- and/or 4-positions and then treating this product with an organic metal reagent, or by N-protecting an optically active 3-haloalanine derivative to thereby give N-protected-aziridine-2-carboxylic acid which is protected by a benzenesulfonyl group substituted by nitro at the 2- and/or 4-positions and then treating this product with an organic metal reagent. According to this process, natural and unnatural optically active amino acids can be produced from inexpensive materials by using simple procedures.
摘要:
An optically active amino acid derivative is produced by N-protecting an optically active 3-haloalanine derivative followed by cyclization, or cyclizing this derivative followed by N-protection to thereby give an optically active N-protected-aziridine-2-carboxylic acid derivative which is protected by a benzenesulfonyl group substituted by nitro at the 2- and/or 4-positions and then treating this product with an organic metal reagent, or by N-protecting an optically active 3-haloalanine derivative to thereby give N-protected-aziridine-2-carboxylic acid which is protected by a benzenesulfonyl group substituted by nitro at the 2- and/or 4-positions and then treating this product with an organic metal reagent. According to this process, natural and unnatural optically active amino acids can be produced from inexpensive materials by using simple procedures.
摘要:
The present invention provides a method for conveniently obtaining a biodegradable polyhydroxyalkanoate by a solvent extraction method. A method for producing a polyhydroxyalkanoate crystal comprises precipitating a polyhydroxyalkanoate crystal using a monohydric alcohol having 4 to 10 carbon atoms as a extraction solvent, keeping a polyhydroxyalkanoate solution containing 0.1 to 10% by weight of water relative to the total amount of the solution warm at 70° C. or higher, and cooling the solution to below 70° C.
摘要:
There is provided a process for preparing a pharmacologically acceptable salt of N-(1(S)-ethoxycarbonyl-3-phenylpropyl)-L-alanyl-amino acid which comprises condensing an amino acid and N-(1(S)-ethoxycarbonyl-3-phenylpropyl)-L-alanine.N-carboxyanhydride under basic condition, carrying out decarboxylation under between neutral and acidic condition to obtain N-(1(S)-ethoxycarbonyl-3-phenylpropyl)-L-alanyl-amino acid, and forming a pharmacologically acceptable salt thereof, wherein the production of a by-product (3): is suppressed by carrying out in an aqueous liquid a series of operations till formation of the pharmacologically acceptable salt or till isolation of the pharmacologically acceptable salt. The present invention enables to prepare the pharmacologically acceptable salt of N-(1(S)-ethoxycarbonyl-3-phenylpropyl)-L-alanyl-amino acid having high quality, in a commercial scale with high yield and economical efficiency.