41 results about "Cefditoren" patented technology

A composition of an amorphous cefditoren pivoxil excellent in stability and releasability; and a process for producing the amorphous composition. The composition comprises cefditoren pivoxil and a pharmaceutically acceptable organic polymer, and is characterized by being obtained by pulverizing crystalline cefditoren pivoxil in the presence of a pharmaceutically acceptable organic polymer and making the cefditoren pivoxil amorphous.

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 present invention provides a process for the preparation of Cefditoren of the formula (I)which comprises acylating 7-amino-cephem carboxylic acids of the general formula (IV)where R3 is hydrogen or trimethylsilyl with thioester derivatives of the formula (II)wherein R1 represents C1-C4 alkyl or phenyl in an organic solvent in the presence of an organic base at a temperature in the range of -10° C. to 30° C.

The invention relates to a preparation method of Cefditoren Pivoxil. The preparation method comprises steps as follows: 7-ACA (3-acetyloxymethyl-5-thio-7-amino-8-oxy-1-nitrogen heterobicyclic octyl-2-ene-2 carboxylic acid) is taken as a starting raw material and is subjected to iodination and Wittig reaction after silanization protection, and a Cefditoren parent nucleus 7-ATCA (7-amino-3-[(Z)-2-(4-methyl-5-thiazole) vinyl]-3-cephem-4-carboxylic acid) is generated; after amino protection of aminothiazole ethyl gallate, a compound 2 is produced from 7-ATCA under catalysis of AlMe3; the compound2 is subjected to an esterification reaction with iodomethyl pivalate under actions of a phase transfer catalyst and an acid adsorbent, the amino protection is removed, and a target product CefditorenPivoxil is obtained. According to the preparation method, reaction conditions are mild, product purity and yield are high, the process is stable, amplification is easy, and the method is applicable to industrial production.

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.

The invention discloses a method for preparing cefditoren pivoxil in the technical field of medicine, which comprises: dissolving a cefditoren pivoxi crude product in a water-soluble solvent; preparing a cefditoren pivoxil organic phase; preparing a cefditoren pivoxil aqueous phase; and adjusting the pH value of the solution, performing acid extraction treatment and menstruum crystallization treatment, and obtaining the cefditoren pivoxil with the purity of 98.1 to 98.8 percent. The method ensures that the cefditoren pivoxil can obtain high-purity products according with pharmacopoeia throughpurification under stable condition by simple operation.