39results about How to "Improve the overall yield of synthesis" patented technology

The invention discloses a preparation method of 16a-hydroxy prednisolone. The preparation method comprises the following steps: dissolving 16a-hydroxy prednisolone acetate into an organic solvent, adding an inert solid carrier adsorbed with strong base as a hydrolysis reaction solid-phase base catalyst, and hydrolyzing 21-acetate to obtain a 16a-hydroxy prednisolone crude product; and carrying out lower alcohol recrystallization on the crude product under the condition of below C4 to obtain a 16a-hydroxy prednisolone competitive product, wherein the refined weight yield is 85% to 90%, and the preparation weight total yield is 75% to 80%. The solid carrier is selected from aluminum oxide, silica gel or calcium carbonate; the base catalyst is selected from sodium carbonate; and the organic solvent is selected from methylbenzene or chloroform. Compared with a traditional method, the method disclosed by the invention is simple and convenient in production operation, impurities generated in traditional production can be greatly reduced, and the total yield for synthesis is greatly improved; compared with the traditional method, the production cost is reduced by 10% to 15%; and a synthetic reaction solvent can be recycled, and industrial production is facilitated.

The invention provides a method for preparing a 16a-hydroxyl prednisolone product. The method comprises the steps: firstly, subjecting 17a-deshydroxy prednisolone acetate, which serves as a starting raw material, and organic peroxy acid to an epoxidation reaction at 16,17 sites in a first organic solvent, so as to prepare epoxide; subjecting the epoxide and glacial acetic acid to a ring-opening reaction under the catalysis of an acid catalyst in a second organic solvent, so as to prepare 16a,21-diacetoxyl prednisolone; then, dissolving the 16a,21-diacetoxyl prednisolone in a third organic solvent, and hydrolyzing acetate of two positions under the catalysis of a solid-phase alkali catalyst, so as to prepare 16a-hydroxyl prednisolone; finally, subjecting the crude 16a-hydroxyl prednisoloneobtained through solid-phase alkali-catalyzed hydrolysis to heated refluxing, decoloring and recrystallization by low carbon alcohols of C4 or less, thereby obtaining the 16a-hydroxyl prednisolone product. The 16a-hydroxyl prednisolone is prepared by the efficient, environment-friendly and cheap method.

The invention relates to a chemical synthetic method of 8-furan-8-oxomethyl caprylate. The method comprises the following steps of adding octanedioic acid and sulfoxide chloride into a reaction bulb, agitating an obtained mixture at a room temperature until a reaction is complete, and distilling to remove the sulfoxide chloride under normal pressure; afterwards, adding a solvent and a catalyst into the reaction bulb to carry out another reaction, dropwise adding methanol into the reaction bulb for quenching, decompressing the reaction bulb and distilling to remove the solvent, dissolving a target product by using an extracting solution to obtain a solution, and distilling the solution under reduced pressure to obtain a yellowish oily 8-furan-8-oxomethyl caprylate pure product. According to the chemical synthetic method of the 8-furan-8-oxomethyl caprylate, a synthetic strategy of a one-pot method is adopted; by proceeding from the low-cost octanedioic acid, the octanedioyl chloride is prepared with a high yield; afterwards, the octanedioyl chloride and furan are subjected to a regioselectivity Friedel-Crafts acylation reaction; finally, acyl chloride at the other end is quenched by using the methanol to directly generate methyl ester to obtain the product; by using the method, the synthetic route of the target product is simplified; the reaction time is greatly shortened; the synthetic total yield is improved; therefore, the production cost is decreased; the chemical synthetic method has the advantages of being low in cost, higher in yield, simple to operate and suitable for industrial production, and the like.

The invention provides a method for preparing delmadinone acetate. The method comprises the following steps that 1,6-didehydro-17a-hydroxyprogesterone is adopted as a raw material to first synthesizea 6-position epoxide, then the epoxide is heated, refluxed, discolored and re-crystallized by using active carbon in lower alcohol of C4 or less to obtain an epoxide product, then the epoxide productis used as a raw material to synthesize a 6-position chloride to obtain delmadinone, and finally by virtue of 17-position esterification, the delmadinone acetate can be obtained. Compared with a traditional synthetic method of the delmadinone acetate, the method of the invention has the advantages of simple process operation, economical and environment-friendly production, high synthetic total yield, good product quality, low production cost and the like.

The invention provides a delmadinone acetate preparation method which comprises the following steps: by taking 1,4-androstadienedione, that is, IDD, as a raw material, firstly, enabling 17-site ketonein IDD molecules to react with acetone cyanohydrins in a first organic solvent under catalysis of an alkali, and introducing beta-hydroxyl and alpha-cyan into the 17-site so as to obtain hydroxyl cyanogens; preparing 1,6-bidehydrogenation-17a-hydroxyl progesterone from the hydroxyl cyanogens in the presence of methyl magnesium halide, a second organic solvent and an acid; and further synthesizinga 6-site epoxy substance, further synthesizing 6-site chloride so as to obtain delmadinone, and finally carrying out 17-site esterification, thereby obtaining delmadinone acetate. Compared with a conventional synthesis method, the delmadinone acetate preparation method provided by the invention has multiple advantages of being simple and convenient in process operation, economic and environmental-friendly in production, high in total synthesis yield, high in product quality, low in production cost, and the like.

The invention provides a preparation method of delmadinone. The preparation method comprises the steps: 1,4-androstadienedione, namely IDD is adopted as a raw material; firstly, 17-position ketone inIDD molecules reacts with acetone cyanohydrin in a first organic solvent under alkali catalysis, and beta-hydroxyl and alpha-cyan are introduced in the 17 position to obtain hydroxyl cyanide; then thehydroxyl cyanide is prepared under presence of methylmagnesium halide, a second organic solvent and acid to obtain 1,6-didehydro-17a-hydroxyprogesterone; and then 6-position epoxy is synthesized, andthen 6-position chloride is synthesized to obtain the delmadinone. Compared with a traditional synthesis method of delmadinone and delmadinone acetate, the preparation method has the multiple advantages that process operation is easy and convenient, production is economical and environmentally friendly, the total yield of synthesis is high, the product quality is good, and the production cost islow.

The invention discloses a preparation method of nitidine chloride. The method comprises the following steps of 1) catalyzing 4,5-dimethoxy-2-(methoxycarbonyl) phenylboronic acid to react with azobenzene bornene to obtain an intermediate 1 by using a metal palladium/ligand; 2) dissolving the intermediate 1 with an organic solvent, then adding trifluoroacetic acid, and conducting a room temperaturereaction to obtain an intermediate 2; 3) methylating the intermediate 2, oxidizing, reducing, and treating with hydrochloric acid to obtain the nitidine chloride. The synthetic route of the method issimpler, and the total synthesis yield of the nitidine chloride is as high as 72% or more.