33 results about "Menadiol" patented technology

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.

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 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 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.

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 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.