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US 4,309,549 AGranted
Benzoxazolone preparation
AssigneeRhone-Poulenc Agrochimie
InventorYvon Querou
Life of this patent
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Abstract
Benzoxazolone is prepared by heating a mixture of ortho-chlorophenol and urea under superatmospheric ammonia pressure, and then continuing heating the medium of reaction, but under atmospheric pressure.
Claims26
A process for the preparation of benzoxazolone comprising, in a first step, heating at an elevated temperature a reaction mixture of ortho-chlorophenol and urea under superatmospheric ammonia pressure until the degree of conversion of the ortho-chlorophenol has essentially stabilized, and thence continuing heating the medium of reaction at an elevated temperature in a second step, but under atmospheric pressure.
Dependencies are inferred from the claim text.