274 results about "Silyl ether" patented technology

Provided are compositions suitable for use in forming a flexible optical waveguide. The compositions include a polymer, having units of the formula (RSiO1.5), wherein R is a substituted or unsubstituted organic group, and a plurality of functional end groups. A first component is provided for altering the solubility of the composition in a dried state upon activation. A second component contains a plurality of functional groups chosen from hydroxy, amino, thiol, sulphonate ester, carboxylate ester, silyl ester, anhydride, aziridine, methylolmethyl, silyl ether, and combinations thereof. The second component is present in an effective amount to improve flexibility of the composition in a dried state before and after activation. Also provided are flexible optical waveguides, methods of forming flexible optical waveguides and electronic devices that include a flexible optical waveguide.

The invention discloses a method for preparing methylnaltrexone bromide and belongs to the technical field of pharmaceutical engineering. The method comprises the following steps of: generating 3-O-t-butyl dimethyl silyl-naltrexone by taking naltrexone hydrochloride as a raw material, t-butyl dimethyl chlorosilane as a protection group and a dipolar aprotic solvent as a medium in the presence of organic base; reacting dimethyl carbonate serving as a methylating agent and the dipolar aprotic solvent serving as the medium with the dimethyl carbonate; and finally, reacting with solution of hydrobromic acid in the water serving as a medium, and distilling at reduced pressure to obtain the methylnaltrexone bromide. The protection group t-butyl dimethyl chlorosilane of phenolic hydroxyl is white solid, has no pungent odor, can generate stable intermediate products at normal temperature, has simple removal step, and is an ideal hydroxyl protective agent. The methylating agent dimethyl carbonate makes reaction environment-friendly, reaction yield higher, and technology simpler; the methylnaltrexone bromide is generated during deprotection; the steps are shortened; and the industrialized production is convenient.

The invention relates to the pharmaceutical field, and concretely relates to a method for preparing vicagrel and derivatives thereof. The method comprises a step 1 of adopting optically-active alkyl sulfonate to carry out selective N-alkylation of 4,5,6,7-tetrahydrothieno[3,2-c]pyridine-2-ol silyl ether, and a step 2 of directly esterifying a product generated in step 1 to obtain vicagrel. The method has the advantages of less side reactions, high yield, high chemical purity and optical purity, low cost, simple operation, and suitableness for the industrialized production.

The invention discloses a method for preparing simvastatin. The method is as follows: a. lovastatin and alkylamine are prepared into lovastatin amide; b. hydroxyl groups in lovastatin amide molecules are protected, and lovastatin amide di-(trimethyl) silyl ether is generated; c. the lovastatin amide dimethyl (trimethyl) silyl ether is subjected to methylation, so as to obtain simvastatin amide di-silyl ether; d. the simvastatin amide di-silyl ether is protected, and simvastatin amide is generated; e. the simvastatin amide is subjected to hydrolysis and is added with ammonia gas, and simvastatin ammonium salt is obtained; and f. the simvastatin ammonium salt is subjected to ring closure to generate the simvastatin. The method takes a composite solvent of tetrahydrofuran and cyclonexane as a solvent for the protective reaction; the lovastatin amide di-(trimethyl) silyl ether can directly perform methylation reaction without alkaline washing and water scrubbing; after water scrubbing of methylate, protective groups are automatically fallen off, thereby the reaction for removing the protective groups is saved and the products can directly perform ammonium salt reaction. The method simplifies the synthesis technique of the simvastatin.