Process for the preparation of the enol lactone of 2-oxocyclohexlidene acetic acid and application to the preparation of 2-cuomaranone
Patent 5773632 Issued on June 30, 1998. Estimated Expiration Date: 
June 26, 2017. 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.
June 26, 2017. 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 References3862133 InventorsAssigneeApplicationNo. 883594 filed on 06/26/1997US Classes:549/307, The other cyclo of the bicyclo ring system is benzene (e.g., phthalides, etc.)549/462, Bicyclo ring system having the hetero ring as one of the cyclos549/471Plural double bonds between ring members of the hetero ringExaminersPrimary: Trinh, Ba K.Attorney, Agent or FirmForeign Patent References
International ClassC07D 307/83Foreign Application Priority Data1996-07-09 FRAbstractA process for the preparation of the enol lactone of 2-oxocyclohexylidene acetic acid wherein(i) glyoxylic acid is allowed to react with cyclohexanone in the presence of a halogen acid in order to obtain a crude reaction product B1, then(ii) said crude reaction product B1 is allowed to react, after solubilisation in an organic solvent, in the presence of a strong acid soluble in said organic solvent or of strongly acid resins, in order to obtain the enol lactone of 2-oxocyclohexylidene acetic acid which is isolated if desired,and application to the preparation of 2-coumaranone. |
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