Crystalline form of cefdinir cesium salt
OwnerVinod Kansal, Dhirenkumar Mistry +2inventors
InventorsVinod Kansal, Dhirenkumar Mistry, Saurabh Pandey, Rakesh Patel
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Abstract
Provided is the cesium salt of cefdinir, processes for its preparation and its use in the preparation of cefdinir.
Claims65
Cefdinir cesium.
A process for preparing cefdinir cesium salt comprising combining cefdinir with water, or a mixture of water and a water-miscible organic solvent, to obtain a reaction mixture, and combining the obtained reaction mixture with a base and a source of cesium ions.
A process for preparing cefdinir cesium salt comprising combining 7-amino-3-vinyl-3-cephem-4-carboxylic acid (7-AVNA), an organic solvent selected from the group consisting of:
- C3-C7 ketone, dimethyl formamide, dimethyl acetamide and cyclic ethers, water, and mixtures thereof, and O-acetyl thioester to obtain a reaction mixture;
- adding an organic base;
- adding C1-C6 halogenated hydrocarbon, C2-C6 ester, or C2-C8 cyclic ether;
- and adding a base and a source of cesium ions to obtain a precipitate.
A process for preparing cefdinir cesium salt comprising reacting 7-amino-3-vinyl-3-cephem-4-carboxylic acid with O-acetyl thioester in a mixture of tetrahydrofuran and water while stirring, cooling the reaction mixture to about 15-20° C., adding triethylamine to the reaction mixture to obtain a pH of about 8.0 to 8.2, adding methylene chloride to the reaction mixture while maintaining the temperature and stirring, separating the organic and aqueous phases, adding ammonium chloride to the aqueous phase to maintain the pH at about 7.8 to about 8.2, adding cesium carbonate solution the aqueous phase to obtain a precipitate of cefdinir cesium.
A crystalline form of cefdinir cesium salt characterized by a powder x-ray diffraction pattern with peaks at 4.7, 9.1, 9.4, 10.7, 12.2, 13.3, 15.9, 16.8, 19.4, 21.5, 22.2, 22.9, 25.8, 26.3, and 27.0±0.2 degrees two-theta.
A process for preparing cefdinir comprising converting cefdinir cesium to cefdinir by reaction with an acid.
Cefdinir having a purity of more than about 99%.
Dependencies are inferred from the claim text.