41 results about "Cefditoren" patented technology

A crystalline substance of Cefditoren pivoxyl is provided which has a high purity and enhanced thermal stability on storage. This crystalline Cefditoren pivoxyl may be prepared by a process comprising a step of dissolving an amorphous form of Cefditoren pivoxyl in an anhydrous, first organic solvent capable of dissolving said amorphous form well therein, and steps of replacing the first organic solvent component of the resulting solution by an anhydrous alkanol of 1 to 5 carbon atoms as a second organic solvent, in such a manner that the firstly prepared solution of Cefditoren pivoxyl in the first organic solvent is mixed with a volume of the alkanol and then is concentrated below 15° C. under reduced pressure, and so on. Thereby, the process proceeds so as to produce a solution containing 50 mg / ml to 250 mg / ml of Cefditoren pivoxyl dissolved in the alkanol alone. From the latter solution, crystals of Cefditoren pivoxyl are induced to deposit by addition of water at a temperature of 0-10° C. The resulting admixture of the concentrated solution of Cefditoren pivoxyl in alkanol with added water and the deposited Cefditoren pivoxyl is then agitated 10° C. or below, to effect a complete crystallization of Cefditoren pivoxyl.

The present invention relates to an improved process for the preparation of Cefditoren of formula (I), the said process comprising the steps of: i) converting the compound of formula (II) to a compound of the formula (III) using TPP and sodium iodide in the presence of THF, water, and base; ii) reacting the compound of formula (III) with 4-methyl-5-formyl-thiazole to produce a compound of formula (IV); iii) deesterifying the compound of the formula (IV) to yield compound of formula (V); iv) converting the compound of formula (V) to compound of formula (VI) in the presence of a base and solvent; v) converting the compound of formula (VI) into compound of formula (VII) by enzymatic hydrolysis; and vi) reacting compound of formula (VII) with compound of formula (VIII) in the presence of solvent and base to produce compound of formula (I).

The invention belongs to the technical field of medicines and particularly relates to a preparation method of cefditoren pivoxil. The preparation method particularly includes following steps: (1) carrying out a reaction between cefditoren mother nucleus 7ATCA and AE-activated ester with dichloromethane as a solvent under an alkaline condition at 0-5 DEG C; (2) performing extraction with pure water and adding a sodium iso-octoate / acetone solution to obtain cefditoren sodium; (3) carrying out a reaction between the cefditoren sodium and iodomethyl pivalate under the alkaline condition at -40 DEG C to obtain a cefditoren pivoxil solution; (4) adding pure water to separate out a crystal to obtain a crude product of the cefditoren pivoxil. The technical scheme also comprises steps of dissolving the crude product of the cefditoren pivoxil in a mixed solution including dichloromethane and anhydrous ethanol, washing the material solution with a 1% sodium bicarbonate solution and pure water, collecting an organic phase, and performing a pressure-reducing evaporate-drying process to obtain the cefditoren pivoxil being higher than 99% in purity and less in impurities. The preparation method is simple in operation, is easy to control, is high in yield, allows the raw material to be obtained easily and is suitable for industrialized large-scale production.