Cyclization process for making oxazolikinones
Patent 5688962 Issued on November 18, 1997. Estimated Expiration Date: 
May 16, 2016. 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.
May 16, 2016. 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.Inventors
AssigneeApplicationNo. 649843 filed on 05/16/1996US Classes:548/225, Chalcogen bonded directly to ring carbon of the oxazole ring548/226, Plural chalcogens bonded directly to ring carbons of the oxazole ring548/228, Chalcogen bonded directly at 5-position of the oxazole ring548/233Nitrogen bonded directly to ring carbon of the oxazole ringExaminersPrimary: Richter, JohannAssistant: Oswecki, Jane C. Attorney, Agent or FirmForeign Patent References
International ClassesC07D 263/04C07D 263/16 C07D 263/46 Foreign Application Priority Data1995-05-26 GBAbstractA process for the synthesis of a compound of general formula II: ##STR1## wherein: R2 and R3 are each independently hydrogen or C1 -C4 alkyl;A is an aromatic or heteroaromatic ring system optionally substituted with one or more substituents as defined herein; and in which any ring nitrogen atom may be quaternised or oxidised;alternatively, any two substituents of the group A may combine to form a fused 5- or 6-membered saturated or partially saturated carbocyclic or heterocyclic ring in which any carbon or quaternised nitrogen atom may be substituted with any of the groups defined herein for A or in which a ring carbon atom may be oxidised;the process comprising cyclising a compound of general formula VII: ##STR2## wherein A, R2 and R3 are as defined for general formula II, R20 is hydrogen, benzyl or benzyl substituted with up to five substituents selected from halo, C1 -C6 alkyl, O(C1 -C6 alkyl) or nitro and R21 is C1 -C8 alkyl, benzyl or benzyl substituted with up to five of the substituents mentioned above for R20. |
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