36 results about "Methyl tosylate" patented technology

A novel process for the synthesis of Lacosamide using D,L-serine as starting material is described, where the methylation reaction of hydroxyl is carried out using an inexpensive base such as NaOH and an inexpensive alkylating agent, non-toxic and non-carcinogenic, such as methyl p-toluenesulfonate; the R enantiomer is isolated from the racemic mixture of Lacosamide after selective hydrolysis of the acetamide, salification of the racemic mixture with a chiral acid (HX*) in an organic solvent, resolution of the diastereoisomeric mixture, preferably by precipitation of the R enantiomer, and subsequent acetylation of the optically pure intermediate.

A new method for synthesizing methoxamine hydrochloride, the method steps: under the protection of nitrogen, add liquid methyl p-toluenesulfonate to a certain amount of potassium carbonate in acetonitrile solution, and control the temperature to 15°C±3°C , slowly drop into the mixture of acetonitrile containing an appropriate amount of hydroquinone. Stir for another 5 minutes, heat up to 83° C. and reflux vigorously for reaction. When reflux occurs, turn off the nitrogen gas, and the reaction will be complete within 22 hours. Then through Friedel-Crafts acylation reaction, oximation reaction, oxime group reduction reaction, ketoamine hydrogenation reaction, and finally the target product was synthesized by an economical and environmentally friendly route. The yields of the 5-step operations were: 94%, 72%, 80%, 79% and 88%, respectively. The invention has the advantages of mild reaction, simple conditions, stable and easy scale-up production, and improved yield compared with the traditional synthesis of methoxamine hydrochloride.

The invention discloses a preparation method for a Clarithromycin intermediate. The method is characterized in that (2',4"-O-bistrimethylsilyl)-erythromycin A-9[O-(1-ethoxy-1-methylethyl)]oxime is used as a raw material, toluene, hexane and dimethyl sulfoxide are used as solvents, bromomethane, iodomethane and methyl p-toluenesulfonate are used as methylation reagents, potassium hydroxide is used as a catalyst, and methylation is carried out so as to prepare the Clarithromycin intermediate. According to the invention, through selection of a solvent system, cooperative control of the amounts of the reaction reagent and the catalyst and synergism of temperature and time, the preparation method for the Clarithromycin intermediate has the advantages of simple process, stable operation, a high conversion rate, low cost, a small amount of waste gas, waste water and industrial residue and suitability for industrial production.

The invention provides a polyurethane adhesive and a preparation method thereof. The polyurethane adhesive comprises diphenylmethane diisocyanate, styrene grafted polyether polyol, epoxide resin, methyl p-toluenesulfonate, polypropylene glycol, polyoxypropylene pentaerythritol ester, an amine catalyst, isophorone diamine, zeolite, castor oil, N-ethyl-N-zinc phenyl dithiocarbamate, resorcinol, triphenylphosphine, a silane coupling agent and an emulsifying agent. The preparation method comprises the following steps of: firstly mixing the diphenylmethane diisocyanate, the amine catalyst, the epoxide resin, the methyl p-toluenesulfonate, the polypropylene glycol, the polyoxypropylene pentaerythritol ester and the zeolite, and then adding the resorcinol and the triphenylphosphine; stirring, and then adding a mixture of the styrene grafted polyether polyol, the isophorone diamine, the castor oil, the N-ethyl-N-zinc phenyl dithiocarbamate, the silane coupling agent and the emulsifying agent to obtain the polyurethane adhesive. The polyurethane adhesive provided by the invention has the advantages of excellent yellowing resistance, ageing resistance, heat resistant property, hydrolysis resistant property and bonding strength.

The invention discloses a synthesis method of a novel anti-influenza drug baloxavir dipivoxil, which uses thiosalicylic acid compound 1 and 1-(halomethyl)-2,3-difluorobenzene compound 2 as starting materials Direct docking to obtain compound 3, and then use PPA ring closure to obtain 7,8-difluorodibenzo[b,e]thiapine-11(6H)-one compound 4, and then obtain the key compound 4 under the catalysis of chiral enzyme Chiral Thiazem Intermediate Compound 5. Then compound 5 is directly condensed with the key chiral fragment compound 6 by Mitsubobu reaction to obtain compound 7, and finally removes the alkyl protection and condenses with ((methoxycarbonyl) oxygen) 4-toluenesulfonic acid methyl ester to obtain the final product compound 9 bar loxavir dipivoxil. This synthetic route reduces the difficulty of enlarging the process operation of the route, reduces the generation of by-products, improves the product purity, and reduces the cost of the route. The specific route: