Preparation of form 1 ranitidine hydrochloride
Patent 5338871 Issued on August 16, 1994. Estimated Expiration Date: 
April 1, 2013. 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.
April 1, 2013. 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 ReferencesNitrovinyl aziridine derivative Process for the recovery of S-(carboxymethyl)-(R)-cysteine and S-(carboxymethyl)-(S)-cysteine Optical resolution process for DL-cysteine Furan derivatives useful for the treatment of gastro-intestinal disorders Patent #: 5075301 InventorsAssigneeApplicationNo. 041354 filed on 04/01/1993US Classes:549/492Nitrogen and the hetero ring are single bonded directly to the same acyclic saturated hydrocarbon groupExaminersPrimary: Ivy, C. WarrenAssistant: Owens, A. A. Attorney, Agent or FirmInternational ClassC07D 307/52AbstractPure Form 1 ranitidine hydrochloride is prepared by a process of crystallization from a solution of ranitidine hydrochloride in a mixed solvent comprising 1 part by volume of at least one lower alkanol such as ethanol and 1-2.0 parts by volume of a C6 -C10 aromatic hydrocarbon such as toluene, and in the presence of seed crystals of pure Form 1 ranitidine hydrochloride. In the preferred process according to the invention, the ranitidine hydrochloride is prepared in situ in the solvent mixture by adding hydrochloric acid to a solution of the free base in the solvent mixture, in the presence of the seed crystals. |
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