Abstract: Dipeptide alkyl esters whose alkyl group contains 3 to 7 carbon atoms can be converted to the corresponding methyl ester compound by a rapid, gentle transesterification in anhydrous methanol in the presence of an alkali metal alcoholate, without racemization occuring on the two chiral carbon atoms.

Abstract: Hydrocinnamic acid derivatives of the formula ##STR1## wherein one or two of the symbols R.sup.1 to R.sup.4 are halogen or methoxy and the others are hydrogen;R.sup.5 is hydrogen or phenyl;R.sup.6 is a residue of the formula ##STR2## R.sup.7 is (C.sub.1 -C.sub.4)-alkyl, (C.sub.2 -C.sub.5)-alkanoylamino-(C.sub.2 -C.sub.5)-alkyl, amino or (C.sub.1 -C.sub.4)-alkoxyphenyl;R.sup.8 and R.sup.9 each, independently, are hydrogen or (C.sub.1 -C.sub.4)-alkyl;R.sup.10 is hydrogen and R.sup.11 is hydroxy or R.sup.10 and R.sup.11 taken together are oxo;R.sup.12 is hydrogen, (C.sub.1 -C.sub.10)-alkyl, pyridylmethyl or carbamoylmethyl;R.sup.13 is hydrogen, (C.sub.1 -C.sub.4)-alkyl and R.sup.14 is hydrogen, (C.sub.1 -C.sub.4)-alkyl, pyridyl, phenyl-(C.sub.1 -C.sub.4)-alkyl, carboxy-(C.sub.1 -C.sub.4)-alkyl, carbamoyl-(C.sub.1 -C.sub.4)-alkyl, (C.sub.1 -C.sub.4)-alkoxy carbonyl-(C.sub.1 -C.sub.4)-alkyl, di-(C.sub.1 -C.sub.4)-alkoxy carbonyl-C.sub.2 -C.sub.5)-alky, piperidino-C.sub.2 -C.sub.

Abstract: A process for making 2,6-disubstituted tyrosine by the noble metal coupling of a disubstituted aromatic halide or diazonium salt with an amino-protected 2-aminoacrylic acid to form a (Z)-.beta.-(disubstituted phenyl)-.alpha.-acylaminoacrylate, and asymmetrically hydrogenating the acrylate to produce the 2,6-disubstituted tyrosine.

Abstract: Compounds of the formula I ##STR1## in which the carboxyl group on carbon atom 3 is orientated in the endo-position relative to the bicyclic ring system of cis-configuration, and in which R.sup.1 denotes hydrogen, allyl, vinyl or a side-chain of a naturally occurring .alpha.-aminoacid, which may be protected, R.sup.2 denotes hydrogen, alkyl, alkenyl or aralkyl, Y denotes hydrogen or hydroxyl and Z denotes hydrogen, or Y and Z together denote oxygen, and X denotes alkyl, alkenyl or cycloalkyl, or aryl which is optionally mono-, di- or tri-substituted by alkyl, alkoxy, hydroxyl, halogen, nitro, amino, alkylamino, dialkylamino or methylenedioxy, or denotes indol-3-yl, a process for their preparation, agents containing these compounds and their use.

Abstract: The present invention provides a dramatically improved process for the preparation of acrylamide and methacrylamide functional monomers, oligomers, and polymers that avoids the use of acidic catalysts which can cause undesired side reactions. The present invention process involves reacting an alkenyl azlactone with a hydroxy functional compound in the presence of a catalytic amount of either a bicyclic amidine or a trivalent phosphorus compound. These efficient basic catalysts provide unexpectedly increased reaction rates under mild conditions.

Abstract: A phenylalanine derivative having the formula (I): ##STR1## wherein A represents ##STR2## B represents ##STR3## wherein m is 0, 1, or 2 and n is 3, 4, or 5; X represents (a) hydroxy, (b) nitro, (c) amino, (d) phenoxy which may be substituted with (i) halogen or (ii) nitro, (e) c.sub.1 -C.sub.4 alkyloxy which may be substituted wit (i) phenyl or (ii) benzoyl, (f) benzoyl, (g) pyridyloxy which may be substituted with (i) halogen or (ii) nitro, or (h) c.sub.1 -C.sub.4 alkyl which may by substituted with halogen;Y represents ##STR4## or --OR.sup.3 wherein R.sup.1 R.sup.2 are independently (a) hydrogen, (b) phenyl which may be substituted with (i) benzoyl, (ii) C.sub.1 -C.sub.4 alkylcarbonyl, (iii) C.sub.1 -C.sub.4 alkyl which may be further substituted with C.sub.1 -C.sub.4 alkoxycarbonyl or hydroxycarbonyl, (iv) C.sub.2 -C.sub.5 alkenyl which may be further substituted with hydroxycarbonyl or C.sub.1 -C.sub.4 alkoxycarbonyl, (v) C.sub.1 -C.sub.

Abstract: Synthesis of phenylserine ester (a) via benzaldehyde and glycine ester using serine hydroxymethyltransferase; and (b) via methyl benzoylacetate. Synthesis of hydroxy-aspartame or derivative by enzymatic coupling of phenylserine or derivative with aspartic acid or derivative. Hydrogenation of the coupled product to give as final product aspartame or analog with related processes and products.

Abstract: Amino group containing curing component (A) for compounds (B) which contain epoxy or 1,3-dioxolan-2-one groups, comprising a reaction product of (a.sub.1) active CH alkyl esters of isocyanate adducts thereof with (a.sub.2) polyamines.Mixtures of (A) and (B) with or without diluents and additives give rapid curing even at low temperatures and high atmospheric humidity and are suitable in particular for paint formulations.

Abstract: This invention relates to bleaching compounds and compositions that provide effective and efficient surface bleaching of textiles over a wide range of bleach solution temperatures. The bleaching compounds of the invention yield a peroxyacid with a polar amide link in the hydrophobic chain when used in the bleaching compositions. In a preferred embodiment, the bleaching compositions of the invention are also detergent compositions.

Abstract: A method for the removal of the formyl group from an ester of an N-formyl peptide or N-formyl aminoacid, in which the ester is reacted with urea in the presence of a polar solvent and a strong acid.

Abstract: Disclosed herein are N-acyl-N-napthoylglycines and methods of their preparation. The N-acyl-N-napthoylglycines are novel aldose reductase inhibitors useful for the treatment or prevention of diabetic complications.

Abstract: 2-(N-Phenylakyl-N-formyl)amino-3-hydroxy-2-propenoic acids are intermediates for mercaptoimidazolecarboxylic acids which are dopamine-.beta.-hydroxylase inhibitors.

Abstract: A composition of matter comprising an acrylamido-acyl or methacrylamido-acyl oligomer derived from at least one nucleophilic oligomer having at least one amino-, hydroxyl-, or thiol-substituted polyoxyalkylene, polyalkyleneimine, polyester, polyolefin, polyacrylate, or polysiloxane oligomer, said nucleophilic oligomer having a molecular weight in the range of 200 to 20,000 is disclosed. Also disclosed are free radically polymerizable monomer-containing compositions containing said oligomers as well as acrylamido- and methacrylamido-acylated polymers which are thermal or photocured products of said oligomers. In addition, a process is disclosed for providing said acrylamido- and methacrylamido-acylated oligomers which are useful, for example, in coatings, films, printing inks, adhesives, and saturants.

Abstract: A method for producing an indan derivative represented by the formula: ##STR1## by condensing an N-(.alpha.-alkoxycarbonylaralkyl)-.alpha.-amino acid with an N-(indan-2-yl)glycine alkyl or aralkyl ester in the presence of a diphenyl phosphorochloridate, and a method for producing another indan derivative having anti-hypertensive activity by using the above intermediate indan derivative are useful for industrial production of the indan derivative having anti-hypertensive activity.

Abstract: A process for producing stable .alpha.-L-aspartyl-L-phenylalanine methyl ester, which comprises heat-treating crystals of .alpha.-L-aspartyl-L-phenylalanine methyl ester having a water content of from 5 to 15% by weight based on wet crystals, at a temperature of higher than 50.degree. C. and lower than 80.degree. for at least 30 minutes.

Abstract: A process for producing dry .alpha.-L-aspartyl-L-phenylalanine methyl ester, which comprises drying wet crystals of .alpha.-L-aspartyl-L-phenylalanine methyl ester by means of an air having an absolute humidity of at least 0.015 kg/kg or at most 0.01 kg/kg.

Abstract: A process for producing dry .alpha.-L-aspartyl-L-phenylalanine methyl ester having an improved solubility by drying wet crystals of .alpha.-L-aspartyl-L-phenylalanine methyl ester, characterized in that the wet crystals of .alpha.-L-aspartyl-L-phenylalanine methyl ester are granulated so that the specific surface area during the drying operation is at least 4 m.sup.2 /g, followed by drying.

Abstract: The invention relates to a process for the preparation of aspartylphenylalanine methyl ester from N-formylaspartylalanine methyl ester by treatment with an acid, characterized in that N-formylaspartylalanine methyl ester is treated at 30.degree.-60.degree. C. with at least 0.5 molar equivalent oxalic acid per mole of N-formylaspartylphenylalanine methyl ester in a solvent mixture in which N-formylaspartylphenylalanine methyl ester dissolves well and in which the oxalic acid salt of aspartylphenylalanine methyl ester is poorly soluble, after which the oxalic acid salt of aspartylphenylalanine methyl ester is removed by filtration, dissolved in water subsequently neutralized with the aid of an inorganic base with formation of free aspartylphenylalanine methyl ester.

Abstract: A method for the production of N-carbobenzoxy-.alpha.-L-aspartyl-L-phenylalanine methyl ester characterized by the reaction of L-phenylalanine methyl ester with fine N-carbobenzoxy-L-aspartic anhydride crystals, is disclosed.

Abstract: New bicyclic compounds, inclusive of salts thereof, of the formula: ##STR1## wherein R.sup.1 and R.sup.2 are the same or different and each represents hydrogen, hydroxyl or lower alkoxy, R.sup.3 is hydrogen or lower alkyl, R.sup.4 is hydrogen, lower alkyl, amino-lower-alkyl or acylamino-lower-alkyl, R.sup.5 is hydrogen, lower alkyl or aralkyl which may be substituted, R.sup.6 is hydroxyl, lower alkoxy, amino or lower alkylamino, and m and n each means 1 or 2, have inhibitory activities of angiotensin converting enzyme and bradykinin decomposing enzyme, and are useful as antihypertensive agents.

Abstract: A process for recovering .alpha.-L-aspartyl-L-phenylalanine methyl ester from a solution containing various methyl ester or demethylated derivatives of .alpha.-L-aspartyl-L-phenylalanine methyl ester and chloride ions is disclosed. This process uses a reverse osmosis membrane having a specific chloride inhibition rate to desalt and concentrate a solution containing a specified ratio of .delta.-L-aspartyl-L-phenylalanine methyl ester to its derivatives until a specific weight ratio of organic chloride ion to the sum of .alpha.-L-aspartyl-L-phenylalanine methyl ester and its derivatives is obtained. This desalted and concentrated solution is then contacted with an aqueous solvent containing methanol and hydrochloride acid to recover high yields of .alpha.-L-aspartyl-L-phenylalanine methyl ester hydrochloride.

Abstract: N-formyl-.alpha.-L-aspartyl-L-phenylalanine methyl ester is obtained by reacting L-phenylalanine methyl ester with N-formyl-L-aspartic acid anhydride in a reaction solvent containing acetic acid or acetic acid and formic acid in a complete mixing type continuous reaction mode.

Abstract: A compound of D-phenylalanine derivative for hypoglycemic use, represented by the general formula ##STR1## R.sup.1 is selected from hydrogen, alkyl of 1 to 5 carbon atoms, aryl of 6 to 12 carbon atoms, aralkyl of 6 to 12 carbon atoms, ##STR2## --CH.sub.2 CO.sub.2 R.sup.3, --CH(CH.sub.3)--OCO--R.sup.3, and --CH.sub.2 --OCO--C(CH.sub.3).sub.3 ; R.sup.2 is selected from groups comprising aryl of 6 to 12 carbon atoms, a hetero six-membered ring, a hetero five-membered ring, cycloalkyl, or cycloalkenyl, any of which groups may have one or more substituents; and R.sup.3 is selected from hydrogen and alkyl of 1 to 5 carbon atoms; the salts thereof, and precursors which can be converted thereto in the human or animal body.Some of the compounds are novel per se.

Abstract: A phenoxyacetic acid represented by the following formula (I) ##STR1## wherein X represents a halogen atom or CF.sub.3, R.sup.1 and R.sup.3 are identical or different and each represents a hydrogen atom or an alkyl group having not more than 5 carbon atoms, R.sup.2 represents a hydrogen atom, a lower alkyl group, a phenyl group, a benzyl group, --CH.sub.2 CH.sub.2 SCH.sub.3, --CH.sub.2 OH, --CH(CH.sub.3)OH, --CH.sub.2 SH, --CH.sub.2 COOCH.sub.3, ##STR2## or R.sup.2 and R.sup.3 together may form --CH.sub.2 CH.sub.2 CH.sub.2 -- or --CH.sub.2 CH.sub.2 CH(OH)--, and n is 0, 1 or 2, or a salt at the carboxyl group of the phenoxyacetic acid of the above formula in which R.sup.1 is a hydrogen atom. The compound is useful, as a herbicide, for eradicating weeds, especially narrow-leaved weeds.

Abstract: Synthesis of phenylserine ester (a) via benzaldehyde and glycine ester using serine hydroxymethyltransferase; and (b) via methyl benzoylacetate. Synthesis of hydroxy-aspartame or derivative by enzymatic coupling of phenylserine or derivative with aspartic acid or derivative. Hydrogenation of the coupled product to give as final product aspartame or analog with related processes and products.

Abstract: A process for producing N-formyl-aspartylphenylalanine or its methyl ester, wherein aspartic acid is reacted with formic acid and acetic anhydride in approximately stoichiometric quantities in the presence or absence of a catalyst and phenylalanine or its methyl ester is directly added to the dehydration mixture. This process has a higher yield of the desired N-formyl-dipeptide and minimizes the amount of by-products and unreacted starting materials.

Abstract: A process for producing dry .alpha.-L-aspartyl-L-phenylalanine methyl ester having an improved solubility from wet crystals of .alpha.-L-aspartyl-L-phenylalanine methyl ester having a water content of at least 20% by weight, which comprises drying the wet crystals at a temperature of higher than 50.degree. C. to obtain moist crystals having a water content of less than 20 and more than 15% by weight, then drying the moist crystals at a temperature of not higher than 50.degree. C. to obtain semi-dry crystals having a water content of less than 5% by weight, and further drying the semi-dry crystals at a temperature of higher than 50.degree. C. to obtain dry crystals of .alpha.-L-aspartyl-L-phenylalanine methyl ester.

Abstract: Methods for the alkylation of substituted amines with trifluorate esters is disclosed.

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: There is disclosed a new vinyl monomer capable of forming polymeric vesicles, micelles, monolayers, and side-chain liquid crystalline polymers. The vinyl monomer is of the formula ##STR1## wherein R.sub.1 is substituted or unsubstituted long chain alkyl or aryl and R.sub.2 is a hydrogen atom, alkyl, or aryl.The side-chain liquid crystalline polymers can be formed by free radical polymerization or by anionic polymerizations techniques. The different reaction methods give polymers of different configuration; the anionic technique results in a polymer having a nitrogen atom in the backbone. The polymers are useful in film and fiber formation and display good toughness.

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: A composition of matter comprising an acrylamido-acyl or methacrylamido-acyl oligomer derived from at least one nucleophilic oligomer having at least one amino-, hydroxyl-, or thiol-substituted polyoxyalkylene, polyalkyleneimine, polyester, polyolefin, polyacrylate, or polysiloxane oligomer, said nucleophilic oliogmer having a molecular weight in the range of 200 to 20,000 is disclosed. Also disclosed are free radically polymerizable monomer-containing compositions containing said oligomers as well as acrylamido- and methacrylamido-acylated polymers which are the thermal or photocured products of said oligomers. In addition, a process is disclosed for providing said acrylamido- and methacrylamido-acylated oligomers which are useful, for example, in coatings, films, printing inks, adhesives, and saturants.

Abstract: An optically active compound having the formula: ##STR1## wherein each of Z and Z' is a single bond, --COO--, --OCO--, --CH.sub.2 CH.sub.2 --, --OCH.sub.2 -- or --CH.sub.2 O--, R is an alkyl group having from 1 to 12 carbon atoms, an alkoxyl group having from 1 to 12 carbon atoms, a cyano group or a halogen atom, each of rings A and B is a 1,4-di-substituted phenylene group or a trans-1,4-di-substituted cyclohexylene group, n is 0 or 1, X is ##STR2## wherein * indicates an optical center, and R' is an alkyl group having from 2 to 12 carbon atoms or ##STR3## where R" is a hydrogen atom, an alkyl or alkoxy group having from 1 to 12 carbon atoms, provided that when X is ##STR4## R is the alkyl group or the alkoxy group.

Abstract: The present invention is directed to a composition and method relating to the preparation of aspartyl peptides having the general formula: ##STR1## where the radical-NHR represents an amino acid or peptide group. In the method, a .beta.-monoester of aspartic acid having the general formula: ##STR2## where R.sub.1 represents a hydrocarbon-containing radical, is reacted with a .beta.-dicarbonyl compound, preferably ethylacetoacetate to protect the aspartyl amino group and form an enamine. The enamine is then coupld to an amino acid or peptide, following which any protecting groups are removed to yield .alpha.-aspartyl peptides without any .beta.-isomer. In its composition aspects, the present invention is directed to novel enamines resulting from reaction of the .beta.-monoester of aspartic acid with a .beta.-dicarbonyl compound.

Abstract: A process for preparing an .alpha.-L-aspartyl-L-phenylalanine methyl ester which comprises the steps of reacting formyl-L-aspartic anhydride with L-phenylalanine in the presence of water at a high pH, to produce formyl-.alpha.-L-aspartyl-L-phenylalanine; removing the formyl group from the formyl-.alpha.-L-aspartyl-L-phenylalanine and esterifying the resultant compound with methanol and hydrogen chloride to produce the hydrogen chloride salt of .alpha.-L-aspartyl-L-phenylalanine methyl ester; neutralizing the hydrogen chloride salt of .alpha.-L-aspartyl-L-phenylalanine methyl ester; and filtering the neutralized solution to produce .alpha.-L-aspartyl-L-phenylalanine methyl ester.

Abstract: Compounds of formula (II) ##STR1## wherein R.sub.1 and R.sub.2 are each separately selected from hydrogen, alkyl, alkenyl and alkynyl groups having up to a maximum of four carbon atoms and being unsubstituted, and alkyl, alkenyl and alkynyl groups having up to a maximum of three carbon atoms and being substituted by one, or in the case of fluoro by one or more, substitutents but with the proviso that when R.sub.1 is hydrogen then R.sub.2 is hydrogen or methyl, or R.sub.1 and R.sub.2 together constitute an ethylene bridging group, and R.sub.3 is a group which under physiological conditions undergoes elimination with the formation of a 3,5-dioxopiperazinyl ring, with the further proviso that the compound is in the meso or erythro configuration when each of R.sub.1 and R.sub.

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: 2-(Fluoromethyl or chloromethyl)-2,5-diaminopentanoic acid, 2-(fluoromethyl or chloromethyl)-2,6-diaminohexanoic acid, and 2-fluoromethyl-2-amino-5-guanidinopentanoic acid, and certain derivatives thereof, are inhibitors of ornithine decarboxylase. Methods of preparing the compounds and derivatives are also described.

Abstract: Derivatives having the general formula: ##STR1## in which the various radicals, A,B,X,R.sub.1, R.sub.2, R.sub.3 and n have indicated definitions. These compounds have in particular enkephalinase-inhibiting, antalgic, antidepressive, antidiarrhea and hypotensive activities.

Abstract: Dipeptides containing C-terminal phosphinothricin of the formula ##STR1## in which phosphinothricin is attached to a--preferably natural--amino acids at the amino group are effective herbicides in the pre-emergence and post-emergence techniques. The compounds are obtained, for example, by reacting phosphinothricin with the hydroxysuccinimide ester of an amino acids which is protected at the amino group in the presence of a base and subsequently splitting off the protective groups.

Abstract: Bicycloheptane substituted amide prostaglandin analogs are provided having the structural formula ##STR1## wherein m is 0 to 4; A is --CH.dbd.CH-- or --CH.sub.2 --CH.sub.2 --; n is 1 to 5; Q is --CH.dbd.CH--, --CH.sub.2 --, ##STR2## or a single bond; R is CO.sub.2 H, CO.sub.2 alkyl, CO.sub.2 alkali metal, CO.sub.2 polyhydroxyamine salt, --CH.sub.2 OH, ##STR3## wherein R.sup.4 and R.sup.5 are the same or different and are H, lower alkyl, hydroxy, lower alkoxy or aryl, at least one of R.sup.4 and R.sup.5 being other than hydroxy and lower alkoxy; p is 1 to 4; R.sup.1 is H or lower alkyl; q is 1 to 12; R.sup.2 is H or lower alkyl; and R.sup.3 is H, lower alkyl, lower alkenyl, lower alkynyl, aryl, arylalkyl, lower alkoxy, aryloxy, arylalkyloxy, amino, alkylamino arylamino, arylalkylamino, lower alkyl-S-, aryl-S-, arylalkyl-S-, ##STR4## (wherein n' is 0, 1 or 2), alkylaminoalkyl, arylaminoalkyl, arylalkylaminoalkyl, alkoxyalkyl, aryloxyalkyl or arylalkoxyalkyl.

Abstract: The present invention relates to a process for producing .alpha.-aspartyl-phenylalanine ester represented by the general formula ##STR1## wherein R' represents an alkyl group having 1 to 4 carbon atoms, by reducing an N-protected-N-hydroxymethyl-.alpha.-aspartyl-phenylalanine ester represented by the general formula ##STR2## wherein R represents an organic mioety which can be substituted reductively by hydrogen, and R' is as defined above, with hydrogen gas or formic acid, in the presence of a reduction catalyst and an aromatic primary amine. According to the present invention, there can be obtained a high purity .alpha.-aspartyl-phenylalanine ester with a high yield.

Abstract: In the process of hydrocarboxylating an .alpha.-enamide with CO and an organic hydroxyl compound to produce a N-acyl-.alpha.-amino acid ester, the improvement comprising using as the organic hydroxyl compound reactant, an organic hydroxyl compound which has a chiral center that is essentially all L or D, thereby producing a reaction mixture having essentially no enantiomeric pairs and containing diastereomeric N-acyl-.alpha.-amino acid esters having two chiral centers.

Abstract: Polyimide precursor compositions are described which may be prepared by rting a biprimary aromatic diamine with a diester-diacid or an aromatic tetraacid, and then with the substantially stoichiometrical complement of an aromatic dianhydride.The polyimide precursor compositions are used in the manufacture of insulating coatings, films, impregnating or enamelling varnishes for electric wires etc., and have excellent qualities of flexibility, adhesiveness and heat resistance.

Abstract: The subject invention relates to novel cyclopropanone hydrate derivatives of the structural formula ##STR1## whereinR.sub.1 and R.sub.2 are selected from the group consisting of --H, --(CH.sub.2).sub.n -- where n is an integer between 1 and 20, preferably 2 and 10, --COCH.sub.2 NH.sub.2, and ##STR2## and R.sub.3 and R.sub.4 selected from the group consisting of --H, --OH, 13 NH.sub.2, --CN, --COOR.sub.5, --COOH, --SH, --(CH.sub.2).sub.n OH, --(CH.sub.2).sub.n NH.sub.2, --(CH.sub.2).sub.n COOH, --(CH.sub.2).sub.n COOR.sub.5, --CCH.sub.3 OH (CH.sub.2).sub.n COOH, halogen and C.sub.7 -C.sub.10 arakyls, where n is an integer between 1 and 20, preferably 1 and 10, and R.sub.5 is an alkyl radical having between 1 and 20, preferably 1 and 10, carbon atoms;and to a process for the synthesis thereof.

Abstract: Disclosed is the hydrocarboxylation of defined enamides with CO and a compound ROH to make amino acids or amido esters, either of which can be hydrolyzed to .alpha.-amino acids.

Abstract: Alkyl N-maleylphenylalanate is prepared by reacting the starting material alkyl L-phenylalanate and maleic anhydride in aqueous solution at a pH of at most 7.5. The reaction products can be isomerized with dipolar aprotic solvents into the corresponding fumaric acid monoamides and thus can be used as an intermediate in the preparation of alkyl .alpha.-L-aspartyl-L-phenylalanate.

Abstract: A process for the isomerization of maleic acid, its monoesters and monoamides in the presence of thiourea in anhydrous conditions at elevated temperature to the corresponding fumaryl forms yields intermediates which are useful in the synthetic pathways of aspartame and other useful polypeptides.