Process for preparing pure crystalline lorazepam
Patent 6350870 Issued on February 26, 2002. Estimated Expiration Date: 
March 5, 2021. 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.
March 5, 2021. 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 References3296249 InventorAssigneeApplicationNo. 799318 filed on 03/05/2001US Classes:540/507The additional chalcogen is bonded directly at the 3-position of the bicyclo ring systemExaminersPrimary: Kifle, BruckAttorney, Agent or FirmInternational ClassesC07D 243/24C07D 243/26 AbstractThe present invention provides a process for preparing crystalline lorazepam substantially free of bound solvent from a lorazepam alcohol solvate or hydrate by suspending the lorazepam solvate in an organic medium selected from ethyl acetate, cyclohexane, dichloromethane, toluene and mixtures thereof. This process is useful in producing the anti-anxiety and sedative agent lorazepam in increased yields. A process for converting lorazepam lower alcohol solvates to lorazepam hydrate is also disclosed. |
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