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US 4,537,988 AGranted
Process for the preparation of 2-(4-hydroxyphenyl)-3-methylbutyric acid
AssigneeAmerican Cyanamid Company
InventorCharles P. Grasso
Life of this patent
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Abstract
An integrated process for the preparation of 2-(4-hydroxyphenyl)-3-methylbutyric acid from the corresponding 2-(4-chlorophenyl)-3-methylbutyronitrile through hydrolysis of the nitrile by strong base to the corresponding carboxylic acid followed by formation of the corresponding phenol by nucleophilic displacement of the chlorine with a strong base in the presence of copper salts, and if so desired metallic copper, is described.
Claims2
A process for the preparation of 2-(4-hydroxyphenyl)-3-methylbutyric acid comprising:
- hydrolyzing 2-(4-chlorophenyl-3-methylbutyronitrile with a concentrated aqueous solution of an alkali metal hydroxide selected from 50 to 80% by weight of aqueous sodium or potassium hydroxide at a temperature from 140.degree. to 200.degree. C. for a period of time from one to ten hours or until the reaction is essentially complete, to the corresponding 2-(4-chlorophenyl)-3-methylbutyric acid, introducing into the reaction mixture an aqueous solution of 2 to 10 molar percent of a cupric salt selected from cupric chloride or cupric sulfate and displacing the halide with hydroxide at a temperature of 190.degree. to 250.degree. C. at a superatmospheric pressure of 2 to 25 kg cm.sup.-2 for 1 to 20 hours, or until the reaction is essentially complete.
Dependencies are inferred from the claim text.