Process for preparing well crystallized alkali metal salts of 3, 7-substituted 7-aminocephalosporanic acid derivatives
Patent 5142042 Issued on August 25, 1992. Estimated Expiration Date: 
November 20, 2010. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
November 20, 2010. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 3822256 Method for producing pure crystalline antibiotic products Patent #: 4912211 InventorsAssigneeApplicationNo. 617804 filed on 11/20/1990US Classes:540/230, Alkyl, hydroxyalkyl, alkoxyalkyl or alkanoyloxyalkyl bonded directly to 3 position540/215, 1-thia-5-aza-bicyclo(4.2.0)octane (including unsaturated; e.g., cepham, etc.)540/228Alkyl, hydroxyalkyl, alkoxyalkyl or alkanoyloxyalkyl bonded directly to 3 positionExaminersPrimary: Rizzo, Nicholas S.Attorney, Agent or FirmInternational ClassC07D 501/12AbstractA process for preparing a well crystallized alkali metal salt of 3, 7-substituted 7-aminocephalosporanic acid derivatives having the general formula: ##STR1## wherein: R1= ##STR2## R2 =CH3 or C1 M=Na or Kfrom the acid-form derivatives. The process includes preparing a 30% suspension by weight of the acid-form derivative in concentrate alcohol containing 3 to 7% of water by weight, and add an alcoholic solution of alkali base to the suspension under room temperature. The alcohol used to dissolve the base also contains 3 to 7% of water. After a reaction time of 5 to 20 minutes, cool the mixture and let the salt crystallize, and separate the latter from the liquid phase. |
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