Abstract: p-Aminophenyl acetate is isomerized to p-acetylaminophenol in the presence of an acid such as acetic acid or phosphoric acid.

Abstract: A triethylene glycol derivative is added to p-dichlorobenzene so as to prevent consolidation and improve flowability of p-dichlorobenzene.

Abstract: An improved process for producing allyl bromides by halogen exchange by reaction of an allyl chloride, with a metal bromide, wherein the reaction is conducted in an aprotic polar solvent. The allyl bromides obtained by the process of the invention are useful as intermediates for producing medicines, agricultural chemicals, dyes, and the like.

Abstract: Pyrimidinyloxy(thio)quinoline derivatives represented by the formula (I) which exhibit an excellent controlling effect for plant diseases and are also safe for crop plants, preparation processes of the derivatives, and agri-horticultural fungicides comprising the derivatives as an active ingredient, are disclosed. ##STR1## In the formula (I), X is an oxygen atom or sulfur atom, Y is a hydrogen atom or halogen atom, Z is a hydrogen atom or methyl, R.sup.1 and R.sup.2 are methoxy or methyl, and n is an integer of 1 or 2.

Abstract: A process for producing a p-hydroxyneophyl m-phenoxybenzyl ether represented by the general formula (II) ##STR1## (X.sub.1 and X.sub.2 are independently a hydrogen atom or a halogen atom) by subjecting a corresponding p-alkoxyneophyl m-phenoxybenzyl ether represented by the general formula (I) ##STR2## (R represents a lower alkyl group, and X.sub.1 and X.sub.2 have the same definitions as above) to ether cleavage, in which process the ether cleavage reaction is effected in an aprotic polar solvent, using a lower alkoxide of an alkali metal or an alkaline earth metal or using a metal hydroxide in the presence of a lower alcohol.

Abstract: A higher yield of the difluorohalomethoxybenzene produced by the reaction of a metal phenolate with dibromodifluoromethane or bromochlorodifluoromethane can be obtained by conducting the addition of a metal alcoholate or a metal hydride as a reaction initiator to a solution or a suspension of an aprotic polar solvent containing the metal phenolate and dibromodifluoromethane or bromochlorodifluoromethane.

Abstract: Crude pentachloronitrobenzene containing hexachlorobenzene and small amounts of acids is treated in the molten state or in a mixture solution of nitrobenzene or chloronitrobenzenes with an inorganic basic substance and then subjected to a distillation under reduced pressure.

Abstract: .alpha.-L-Aspartyl-L-phenylalanine methyl ester having low hygroscopicity is prepared by bringing a cake of .alpha.-L-aspartyl-L-phenylalanine methyl ester, which cake has been obtained by solid-liquid separation through a desired preparation process of .alpha.-L-aspartyl-L-phenylalanine methyl ester, into contact with an organic solvent of uniform phase so as to treat the cake with the organic solvent, subjecting the resulting mixture of the cake and organic solvent to solid-liquid separation to obtain a cake, and then drying the last-mentioned cake at a temperature not higher than 60.degree. C. The organic solvent is dry or contains water in an amount up to 30 wt.%.

Abstract: .alpha.-L-aspartyl-L-phenylalanine methyl ester or the hydrohalide thereof is prepared by esterifying .alpha.-L-aspartyl-L-phenylalanine or .alpha.-L-aspartyl-L-phenylalanine which has been formed in situ by treating an N-protected-.alpha.-L-aspartyl-L-phenylalanine in an aqueous solution of sulfuric acid or a methanol-containing aqueous solution of sulfuric acid in the presence of an alkali metal halide or alkaline earth metal halide in a medium composed of sulfuric acid, water and methanol, thereby to allow the resulting .alpha.-L-aspartyl-L-phenyl-alanine methyl ester to precipitate as its corresponding hydrohalide, and then isolating the hydrohalide; and when the preparation of the methyl ester is desired, neutralizing the hydrohalide.

Abstract: A method for preparing .alpha.-L-aspartyl-L-phenylalanine methyl ester having improved solubilization by the isolation thereof from an aqueous medium containing at least one additive selected from the group consisting of sodium alginate, sodium salt of carboxymethylcellulose, sodium starch glycolate and sodium polyacrylate.

Abstract: This invention relates to an improved process for preparing .alpha.-L-aspartyl-L-phenylalanine methyl ester. More specifically, it relates to a process for preparing .alpha.-L-aspartyl-L-phenylalanine methyl ester which comprises treating, as a raw material, N-formyl-.alpha.-L-aspartyl-L-phenylalanine in methanol in the presence of an acid to form .alpha.-L-aspartyl-L-phenylalanine dimethyl ester, hydrolyzing the .alpha.-L-aspartyl-L-phenylalanine dimethyl ester by bringing it into contact with hydrochloric acid in the presence of methanol as desired, separating the thereby-precipitated .alpha.-L-aspartyl-L-phenylalanine methyl ester hydrochloride and neutralizing the hydrochloride. Further, this invention also provides a process for preparing .alpha.-L-aspartyl-L-phenylalanine methyl ester capable of using, as a raw material, N-formyl-.alpha.-L-aspartyl-L-phenylalanine which contains N-formyl-.beta.-L-aspartyl-L-phenylalanine in an amount of 30% by weight or less.

Abstract: Disclosed herein is a process for preparing .alpha.-L-aspartyl-L-phenylalanine methyl ester or its hydrochloride from 5-benzyl-3,6-dioxo-2-piperazine acetic acid or its methyl ester, prepared without using L-penylalanine methyl ester which involves problems in its stability, as a raw material. Specifically, the process comprises: bringing 5-benzyl-3,6-dioxo-2-piperazine acetic acid in the presence of methanol or 5-benzyl-3,6-dioxo-2-piperazine acetic acid methyl ester in the presence or absence of methanol into contact with hydrochloric acid; isolating the thereby deposited .alpha.-L-aspartyl-L-phenylalanine methyl ester hydrochloride; and neutralizing said hydrochloride with an alkali as required. Preparation processes of 5-benzyl-3,6-dioxo-2-piperazine acetic acid or its methyl ester are also disclosed.

Abstract: The present invention relates to a process for preparing .alpha.-L-aspartyl-L-phenylalanine methyl ester or its hydrochloride. .alpha.-L-aspartyl-L-phenylalanine methyl ester or its hydrochloride is prepared by a process comprising: condensating N-formyl-L-aspartic acid anhydride and L-phenylalanine in water or in water containing methanol at a pH in the range of 7-12 to form N-formyl-.alpha.-L-aspartyl-L-phenylalanine; acidifying the reaction mixture successively with hydrochloric acid in the presence of methanol without isolating the N-formyl-.alpha.-L-aspartyl-L-phenylalanine so as to bring it into contact with hydrochloric acid in the presence of methanol for reaction and thereby to deposit .alpha.-L-aspartyl-L-phenylalanine methyl ester hydrochloride; separating the .alpha.-L-aspartyl-L-phenylalanine methyl ester hydrochloride; and neutralizing said hydrochloride as required.

Abstract: This invention relates to an improved process for preparing N-formyl-.alpha.- aspartyl phenylalanine. More specifically, it relates to a process for preparing N-formyl-.alpha.-aspartyl phenylalanine by condensating N-formyl aspartic acid anhydride and phenylalanine which comprises effecting the condensation reaction in a water medium while maintaining the pH during the reaction in the range of 7-12 and at a reaction temperature of 50.degree. C. or below.

Abstract: A process for preparing an N-acylphenylalanine represented by the formula (II): ##STR1## wherein R.sub.3 and R.sub.4 mean individually a hydrogen atom or an alkyl, alkoxy, phenoxy, hydroxy or methylenedioxy group, and R denotes a methyl or phenyl group, which comprises catalytically reducing an N-acyl-.beta.-phenylserine represented by the formula (I): ##STR2## wherein R.sub.1 and R.sub.2 mean individually a hydrogen atom or an alkyl, alkoxy, phenoxy, benzyloxy or methylenedioxy group, and R has the same meaning as defined in the formula (II), in the presence of a reducing catalyst or both reducing catalyst and acid, in a solvent.

Abstract: Disclosed herein is a process for producing an N-acyl-substituted or unsubstituted phenylalanine comprising hydrolyzing a 2-substituted-4-substituted or unsubstituted benzylidene-5-oxazolone with alkali, adjusting pH of the reaction solution containing its hydrolysis product with acid at 5-9 and reducing the resultant reaction solution catalytically in the presence of a palladium or platinum reducing catalyst.In accordance with the process of the present invention, time duration required for effecting the reduction can be shortened markedly in comparison with the reduction in an aqueous strong alkaline solution. Moreover, the catalyst recovered after completion of the reduction can be used repeatedly without any additional treatment and without any observed lowering in its activity. Accordingly, the reduction using the recovered catalyst may proceed in practically the same time as in the case of using a fresh catalyst.

Abstract: In the production of a .beta.-phenylserine by reacting glycine with a benzaldehyde in the presence of an alkali and treating the product with an acid, a novel process which comprises carrying out the reaction in a mixed solvent composed of water and a hydrophobic organic solvent. The presence of a phase transfer catalyst or a surface-active agent in this reaction system promotes the reaction and the .beta.-phenylserine can be obtained in a high yield.

Abstract: .beta.-Chloroalanine is prepared by reacting in an aqueous medium an aziridine-2-carboxylate with hydrogen chloride in an amount of 2.0-5.0 moles per mole of the aziridine-2-carboxyalte and causing the thus-formed .beta.-chloroalanine to selectively crystallize out from the liquid reaction mixture. Since the solution recovered after the isolation of the crystallized .beta.-chloroalanine still contains .beta.-chloroalanine and by-produced .alpha.-chloro-.beta.-alanine dissolved therein, they may be converted into an aziridine-2-carboxylate by treating them with a base to recirculate it for reuse.

Abstract: DL-cystein is produced by reacting a .beta.-halogenoalanine with a trithiocarbonate to obtain the mono(aminocarboxyethyl) ester of trithiocarbonate and then subjecting the ester to acid decomposition. The above process requires mild reaction conditions, is easy to carry out its reactions and can afford DL-cystein with high yield. It is thus an excellent production process of DL-cystein from the industrial viewpoint.

Abstract: A process for producing aziridine-2-carboxylic acid or its salts is provided which comprises treating an alpha-halogeno-beta-aminopropionitrile or its mineral acid salt with an alkali or alkaline earth metal hydroxide in water or in a water-containing organic solvent. In a preferred embodiment, aziridine-2-carboxylic acid or its salt is produced by treating the reaction mixture containing an alpha-halogeno-beta-aminopropionitrile obtained by reacting an alpha, beta-dihalogenopropionitrile or an alpha-halogenoacrylonitrile with ammonia, with an alkali or alkaline earth metal hydroxide in the presence of water without isolating the alpha-halogeno-beta-aminopropionitrile from the reaction mixture beforehand.