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US 4,309,550 AGranted
Benzoxazolone preparation
AssigneeRhone-Poulenc Agrochimie
InventorYvon Querou
Life of this patent
Estimating the term…
Abstract
Benzoxazolone is prepared by heating ortho-chlorophenol under superatmospheric ammonia pressure, and thence by adding urea to the medium of reaction and continuing the heating of same, but under atmospheric pressure.
Claims23
A process for the preparation of benzoxazolone, comprising, in a first step, heating ortho-chlorophenol at an elevated temperature under superatmospheric ammonia pressure until the degree of conversion of the ortho-chlorophenol has essentially stabilized, and thence, in a second step, adding urea to the medium of reaction and continuing heating same at an elevated temperature, but under atmospheric pressure.
Dependencies are inferred from the claim text.