摘要:
There is disclosed an advantageous mixed acid anhydride production method of formula (1): R1C(O)OY(O)n(R2)p (1) wherein R1, R2 and Y denote the same as defined below, n and p denote an integer of 1 or 2, which is characterized by adding a carboxylic acid of formula (2); R1COOH (2) wherein R1 denotes a hydrogen atom, an optionally substituted alkyl group or the like, an organic base to a solution of a carboxylic acid activating agent of formula (3); (R2)pY(O)nX (3) wherein R2 denotes an optionally substituted aliphatic hydrocarbyl group or the like, Y denotes a carbon atom, a phosphorus atom, or a sulfur atom, and X denotes a chlorine atom or the like.
摘要:
The present invention provides a process for preparing optically active azetidine-2-carboxylic acids using readily available reagents of relatively low price in the industry. Thus, there is provided optically active azetidine-2-carboxylic acid, and a process for producing the same by subjecting optically active N-(alkylbenzyl)azetidine-2-carboxylic acid represented by the formula (1): ##STR1## to hydrogenolysis in the presence of a catalyst.
摘要:
A process for producing lactams of formula (1) below, including the step of reacting lactones of formula (2) below with imides of any of formulae (3a), (3b) and (3c) to thereby obtain corresponding carboxylic acids (step A); the step of esterifying the carboxylic acids into corresponding esters (step B); and the step of reacting the esters with amines to thereby obtain lactams of the formula (1) (step C). In the formulae (1)-(2) and (3a)-(3c), when R3 and R4 are simultaneously hydrogen atoms, R is a substituted methylene or optionally substituted polymethylene; when at least one of R3 and R4 is a substituent other than hydrogen atom, R is an optionally substituted methylene or polymethylene; each of R3, R4, R5 and R6 independently is a hydrogen atom, a halogen atom, cyano, etc.; each of A1, A2, A3, A4, A5, A6, A7, A8, A9 and A10 independently is a hydrogen atom, a halogen atom, nitro, etc.; and M is a hydrogen atom or an alkali metal atom.
摘要:
3-�4-(4-Phenyl-1-butoxy)benzoyl!amino-2-hydroxyacetophenone is prepared by reacting a benzoate ester with a halobutylbenzene in the presence of a basic compound and an aprotic polar compound in an aromatic hydrocarbon solvent to obtain a corresponding ether, alkali hydrolyzing the ether in an aromatic hydrocarbon solvent and precipitating a hydrolysate with an acid to obtain 4-(4-phenyl-1-butoxy)benzoic acid, reacting a halogenating agent with this benzoic acid derivative in an aromatic hydrocarbon solvent to obtain an acid halide, and reacting the acid halide in an aromatic hydrocarbon solvent with a corresponding aromatic amine.
摘要:
The present invention concerns a process for producing crystals of 3-amino-2-hydroxyacetophenone salt having a high bulk density and improved flow properties, by treating 3-amino-2-hydroxyacetophenone of formula (1) ##STR1## or hydrogen halide salt thereof with sulfuric acid, in a solvent.
摘要:
An original to be lithographically reproduced is classified according to density distribution into one of a plurality of classes established on the basis of various high quality standard printed reproductions by comparing the density distribution patterns of the original and the standard reproductions. The patterns indicate relative frequency of density values in the entire density range. After being classified, the original is reproduced utilizing a standard color separation tone curve for a scanner that corresponds to the compared and selected standard reproduction. Alternatively a reference tone curve based on a grey scale may be used with a correction according to the difference between the reference tone curve and the standard tone curve. Also the reference tone curve may be corrected with the difference between the original density distribution pattern and the selected standard density distribution pattern.An apparatus for use in the processes is also disclosed.
摘要:
A process for producing proline derivatives of formula (1) below or acid adduct salts thereof, including: the step of reacting N-protected pyrrolidinones of formula (2) below with reducing agents to thereby obtain N-protected pyrrolidinols of formula (3) below (step A); the step of reacting the N-protected pyrrolidinols obtained in the step A with cyanating agents to thereby obtain N-protected cyanopyrrolidines of formula (4) below (step B); the step of reacting the N-protected cyanopyrrolidines obtained in the step B with alcohols and bases to thereby obtain imidates of formula (5) below and treating the imidates with acids to thereby obtain N-protected prolines of formula (6) below (step C); and the step of treating the N-protected prolines obtained in the step C with acids (step D). In formulas (1)-(6) below, any two out of R1, R2, R3, R4, R5 and R6 are bonded with each other to thereby form an optionally substituted C1-C4 polymethylene; and R7 is an optionally substituted C1-C10 linear alkyl, etc.
摘要:
The present invention is directed to a method for purifying pyruvic acid compounds, which method comprises reacting a pyruvic acid compound of general formula (I): wherein R1 is an optionally substituted lower alkyl group, a lower alkenyl group, a lower alkynyl group, a cycloalkyl group, an aryl group, or a heterocyclic group, and R2 is a lower alkyl group, with a bisulfite of general formula (II): MHSO3 (II) wherein M is NH4 or an alkali metal, to give a bisulfite adduct of the pyruvic acid compound and then decomposing the adduct with an acid. According to the present invention, pyruvic acid compounds can be purified by simple and easy procedures without using purification techniques such as distillation or column chromatography, and the above method is advantageous as a process for the production on an industrial scale.
摘要:
The present invention provides a process for preparing optically active azetidine-2-carboxylic acids using readily available reagents of relatively low price in the industry. Thus, there is provided optically active azetidine-2-carboxylic acid, and a process for producing the same by subjecting optically active N-(alkylbenzyl)azetidine-2-carboxylic acid represented by the formula (1): ##STR1## to hydrogenolysis in the presence of a catalyst.
摘要:
Disclosed is a taste enhancing agent for achieving sufficient saltiness or sweetness even in cases where the salt content or sugar content in food is reduced. Specifically disclosed is a taste enhancing agent which contains one or more substances selected from among linear aliphatic aldehydes having 3-10 carbon atoms and linear aliphatic alcohols having 4-10 carbon atoms as active ingredients. The amount of salt content or sugar content added to food can be reduced by adding the taste enhancing agent to the food.