33 results about "Menadiol" patented technology

The present invention relates to a process for preparing enriched isopulegol by crystallization from a melt comprising isopulegol. The invention relates specifically to a process for preparing enantiomerically enriched n-isopulegol proceeding from optically active isopulegol having a relatively low enantiomeric excess by crystallization from the melt. The invention further relates to a process for preparing menthol proceeding from enantiomerically and / or diastereomerically enriched n-isopulegol prepared by crystallization from the melt.

The invention relates to a menthol perfume precursor compound, a preparation method and application of the menthol perfume precursor compound, belonging to the technical field of perfume chemistry. The compound provided by the invention is the compound as shown in formula (I) described in the specification or the salt of the compound as shown in the formula (I). The preparation method comprises the following steps: by taking menthol and succinic anhydride as raw materials and reacting under the catalytic effect of p-toluenesulfonic acid, thereby acquiring monobutyl succinate monoester; reacting monoester with thionyl chloride, thereby acquiring acyl chloride; reacting acyl chloride with maltol, thereby acquiring the final product (menthol maltol ester). The compound acquired according to the technical scheme provided by the invention has high stability; the volatility of the compound is lower than that of the traditional perfume menthol; the compound has peppermint fragrant and sweet flavor; the operation process is simple; the application prospect is wide.

A simple, high-yield process for making menthyl lactate (ML) is disclosed. Menthol and lactic acid react to produce a mixture comprising menthyl lactate and one or more higher lactoyl esters of ML. Hydrolysis of the esterification mixture follows in the presence of aqueous base under conditions effective to convert the higher lactoyl esters to menthyl lactate. Coincidentally, the conditions minimize hydrolysis of menthyl lactate to menthol, thereby maximizing the overall yield of ML.

The invention relates to a 4-dimethylaminopyridine supported catalyst used for esterification reaction of lactic acid and menthol. A catalyst carrier is attapulgite; a 4-dimethylaminopyridine catalyst supported on the attapulgite is prepared by an impregnation method first, and the 4-dimethylaminopyridine catalyst can be used for catalyzing and synthesizing the menthol ester lactate; and the yield of the menthol ester lactate can reach over 90 percent under the optimizing condition. The 4-dimethylaminopyridine supported catalyst has the advantages of high activity, capability of being used repeatedly and the like and is easy to separate. The menthol ester lactate is fresheners widely used in spices, oral cavity care and cosmetics.

The invention relates to a chiral nitrogen-phosphorus ligand and a preparation method thereof, and a method for splitting racemic menthol. According to the splitting method, racemic menthol reacts with allyl ester under the action of a catalyst formed by transition metal salt and a chiral nitrogen-phosphorus ligand, so as to obtain chiral L-menthol and D-menthol under the action of a catalyst formed by a transition metal salt and a chiral nitrogen-phosphorus ligand. The optical purity of the pure L-menthol and D-menthol is greater than 99%, and the yield is greater than 95%.

A simple, high-yield process for making menthyl lactate (ML) is disclosed. Menthol and lactic acid react to produce a mixture comprising menthyl lactate and one or more higher lactoyl esters of ML. Hydrolysis of the esterification mixture follows in the presence of aqueous base under conditions effective to convert the higher lactoyl esters to menthyl lactate. Coincidentally, the conditions minimize hydrolysis of menthyl lactate to menthol, thereby maximizing the overall yield of ML.

The invention relates to a novel method for synthesizing menadiol acetate, which includes the steps: reducing 2-methyl-1,4-aryl-quinone to 2-methyl-1,4-aryl-diphenol via anhydrous zinc chloride and zinc acetate in the presence of HAc (ethanoic acid), then carrying out backflow reaction by means of acetylation of (CH3CO)2O ( acetic anhydride) under the catalysis of NaAc (sodium acetate) to obtain crude menadiol acetate, and obtaining the menadiol acetate after purification. The reduction reaction of 2-methyl-1,4-naphthoquinone can be still completely carried out without adding excessive zinc powder, so that severe waste of the zinc powder is avoided, and a large potential safety hazard that the excessive zinc powder is unsafe in placement after being separated and easy to spontaneously combust is avoided. The method is mild in reaction condition, suitable for industrialized production and high in yield.

The invention relates to a novel method for synthesizing menadiol acetate, which includes the steps: reducing 2-methyl-1,4-aryl-quinone to 2-methyl-1,4-aryl-diphenol via anhydrous zinc chloride and zinc acetate in the presence of HAc (ethanoic acid), then carrying out backflow reaction by means of acetylation of (CH3CO)2O ( acetic anhydride) under the catalysis of NaAc (sodium acetate) to obtain crude menadiol acetate, and obtaining the menadiol acetate after purification. The reduction reaction of 2-methyl-1,4-naphthoquinone can be still completely carried out without adding excessive zinc powder, so that severe waste of the zinc powder is avoided, and a large potential safety hazard that the excessive zinc powder is unsafe in placement after being separated and easy to spontaneously combust is avoided. The method is mild in reaction condition, suitable for industrialized production and high in yield.

The invention discloses a method for preparing L-menthyl glyoxylate-hydrate through catalysis of heteropoly acid. The method comprises the following steps: by taking cyclohexane as a water-carrying agent, and heating and backflowing and dehydrating L-menthol and glyoxylic acid water solution under the catalysis of heteropoly acid, to obtain a reaction liquid A; separating the reaction liquid A so as to remove heteropoly acid, and separating to obtain an organic layer; directly adding the organic layer into a sodium sulfite water solution and a sodium hydrogen sulfite water solution, and fully reacting to obtain a reaction liquid B; separating the reaction liquid B to obtain a water layer, regulating the pH value of the water layer to be 6.8-7.5 through base, then adding formaldehyde water solution, and hydrolyzing to obtain the L-menthyl glyoxylate-hydrate. The method is convenient to operate, and the catalysis of the heteropoly acid has both advantages of liquid acid catalysis and solid acid catalysis; the organic layer obtained by filtering the reaction liquid A to remove heteropolyacid, and filtering is not required for the regulation of pH value, so that the emission of waste acid and salt in the production process can be reduced.

The invention discloses a catalyst for preparing an L-menthol intermediate d-citronellal and a preparation method thereof. The catalyst is characterized in that the structure is [Rh(PS-Binap)2]<+>Y<->, wherein Y<-> is ClO4<->, PF6<-> or BF4<->; and Bingap is (-)-2,2'-bis-(diphenylphosphine)-1,1'-binaphthyl. The catalyst has very excellent physicochemical properties. When the catalyst is subjected to asymmetric hydrogen migration, myrcene amine can be basically obtained by utilizing a quantitative method, and nearly optically-pure d-citronellal can be obtained by carrying out simple acidic hydrolysis on the myrcene amine. The d-citronellal obtained by utilizing the method does not need to be purified and can be subjected to cyclization and high-pressure hydrogenation to produce a target product L-menthol.

The invention discloses a feeding manner for preparing L-monomenthyl glutarate with glutaric anhydride and menthol and belongs to the field of organic chemical synthesis. According to the method takes the glutaric anhydride and the menthol as the raw materials and artificial zeolite as the catalyst and comprises adding in solvent for dissolution, and after the temperature rises, reducing temperature and removing the solvent to achieve solvent-less reaction and further to obtain the L-monomenthyl glutarate. The feeding manner for preparing the L-monomenthyl glutarate mainly solves the problem that, during the process of preparing the L-monomenthyl glutarate through solvent-less reaction, the menthol can easily sublimate to result in low conversion ratio, so that the material cost for preparing the L-monomenthyl glutarate can be reduced, the shortcoming of high viscosity and stirring difficulty at the beginning of the solvent-less reaction can be avoided, subsequent processes can be facilitated, and a series of problems caused by sublimation of the menthol can be eliminated. The feeding manner for preparing the L-monomenthyl glutarate can improve the conversion rate of the menthol from originally 73% to more than 87%.

The invention relates to preparation methods of glyoxylic acid L-menthyl alcohol ester and a monohydrate of the glyoxylic acid L-menthyl alcohol ester, and belongs to the technical field of fine chemical industry. The glyoxylic acid L-menthyl alcohol ester is prepared by the following steps: reacting L-menthol with monohalogen or dihalogen acetyl halide or anhydride to generate monohalogen or dihalogen acetic acid L-menthyl alcohol ester; and reacting in the presence of a pro-oxidant to obtain the glyoxylic acid L-menthyl alcohol ester. The monohydrate of the glyoxylic acid L-menthyl alcohol ester is prepared by the following steps: cooling and diluting a reaction solution using monohalogen acetic acid L-menthyl alcohol ester as a raw material; treating by using a dimethylsulfoxide (DMSO) solution of P2O5 and triethylamine to obtain the glyoxylic acid L-menthyl alcohol ester; washing, extracting and concentrating a reaction solution using dihalogen acetic acid L-menthyl alcohol ester as a raw material to obtain the glyoxylic acid L-menthyl alcohol ester; and treating by using sodium hydrogen sulfite and formaldehyde to obtain the monohydrate of the glyoxylic acid L-menthyl alcohol ester. The total yield of the glyoxylic acid L-menthyl alcohol ester synthesized by the technology can reach over 72 percent; the total yield of the monohydrate of the glyoxylic acid L-menthyl alcohol ester can reach over 80 percent; the purity can reach over 99.5 percent; the technical process is simple and convenient; the raw materials are available; the yield is high; the product purity is high; and the process is suitable for industrial production.

Process for preparation of MK-7 type of vitamin K2 is characterized by attaching hexaprenyl chain of “all-trans” configuration to monoprenyl derivative of menadiol following “1+6” synthetic strategy. According to the invention, a-sulfonyl carbanion generated in situ from the protected monoprenyl menadiol of the formula (II), wherein R1 represents C1-3-alkyl group, is reacted with hexaprenyl halide of the formula (VII), wherein X represents halogen atom, preferably bromine, both Z′ and Z′ represent H or one of Z′ and Z″ represents H and the other represents phenylsulfonyl group —SO2Ph in the alkylation reaction. The hexaprenyl halide of formula (VII) is obtained by coupling two triprenyl units in alkylation reaction, with or without separation of the intermediates.

A method for prepare optically-pure L-menthone and a catalyst for the method are provided. Under the action of oxidation catalyst, L-menthol in menthol is selectively oxidized to prepare the optically-pure L-menthone. The oxidation catalyst comprises a chiral salen manganese compound and hydrogen peroxide. High stereoselectivity synthesis of L-menthone is realized and the optical purity of the product can reach 99 ee%.

This invention relates to a menadiol sodium-diphosphare tablet and preparing method thereof. In which 2-methyl-1, 4-hydronaphthoquinone is used as raw material which is processed through reduction, phosphorylation etc.to obtain 2-methyl-1,4-naphthohydroquinone di-tetra-sodium-salt hexahydrate, then according normal pharmaceutical method to prepare menadiol sodium-diphosphare tablets. By proof test, the gain rate of the menadiol sodium-diphosphare can be up to 92.5%, purity can be up to 99.7% which are fully suitable to the following pharmaceutical processes.

The present invention provides a food and drink, an oral composition, or a fragrance composition that imparts a refreshing refreshing feeling obtained by using menthol, which can enhance the refreshing feeling without increasing the content of menthol and improve the duration of the refreshing feeling Furthermore, it is a cooling agent composition which is excellent in workability when blended in products such as chewing gum. The powdered cooling agent composition is powdered by contacting a mixture containing a cooling sensation substance and a stabilizer with a low-temperature airflow in an atomized state, and the cooling sensation substance contains menthol and menthol selected from 3-hydroxybutyrate ester, menthyl lactate, menthyl glutarate, 3‑L‑menthoxypropane‑1,2‑diol, menthyl acetate, isopulegol, N‑{(ethoxycarbonyl)methyl}‑para Menthol analogues of one or more of menthane-3-carboxamide and menthone 1,2-glycerol acetal.

The invention discloses a method for chiral synthesis of levorotatory menthol. In the process, dextrorotatory pulegone is used as a starting material; catalytic hydrogenation is carried out on the dextrorotatory pulegone by a chiral rhodium catalyst to generate levorotatory menthone; and the catalytic hydrogenation is carried out on the levorotatory menthone by a chiral ruthenium catalyst to synthesize the levorotatory menthol. In the process for synthesizing the levorotatory menthol through an asymmetric synthesis technology, the yield of the levorotatory menthone is more than 90%, the ee value of the levorotatory menthone is more than 99%, the total yield of the levorotatory menthol is greater than 83%, the ee value of the levorotatory menthol is greater than 98%, and the specific rotation is from-49 degrees to -50 degrees. The synthetic process is simple and is suitable for industrial production of the levorotatory menthol in a large scale, and the prepared levorotatory menthol hasthe advantages of high yield, good selectivity, high catalyst activity and other characteristics, is simple to recover.

The invention relates to a menadiol diphosphonate sodium compound and pharmaceutical preparation for treating hypoprothrom-binemia caused by various reasons, particularly to a menadiol diphosphonate sodium freeze-dried injection and its preparing process by using sodium metabisulfite as the stabilizer, sodium chloride as the isotonic agent, the prepared menadiol diphosphonate sodium freeze-dried injection has good stability and pharmaceutical effect, thus can be applied clinically.