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US 6,281,383 B1Granted
Process for the preparation of α,α- dimethylphenylacetic acid from α,α-dimethylbenzyl cyanide under normal pressure
AssigneeAventis Pharma Deutschland GmbH
InventorsGerhard Korb, Hans-Wolfram Flemming, Rudolf Lehnert, Wolfgang Rybczynski
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Abstract
A process for obtaining α,α-dimethylphenylacetic acid wherein α,αdimethylbenzyl cyanide is reacted in the presence of sodium hydroxide, water and a C4- and/or C5-alcohol at temperatures above about 100° C. and the α,α-dimethylphenylacetic acid is obtained by acidification.
Claims16
A process for preparing the compound of the formula I:
- which comprises the steps of
- (a) reacting a compound of the formula II:
- in the presence of water, sodium hydroxide, and at least one C4- or C5-alcohol, at a temperature of more than 100° C. to give the corresponding carboxylic acid salt;
- and
- (b) adding an acid to the carboxylic acid salt to obtain the compound of the formula I.
2 more elements
A process for preparing the compound of the formula I:
- which comprises the steps of
- (a) reacting a compound of the formula II:
- in the presence of about 120 mol to about 250 mol of water and about 150 mol to about 300 mol of sodium hydroxide per 100 mol of the compound of the formula II, and about 0.6 kg to about 1.0 kg of at least one C4- or C5-alcohol per 1 kg of the compound of the formula II, at a temperature of about 110° C. to about 130° C. to give the corresponding carboxylic acid salt;
- and
- (b) adding an acid to the carboxylic acid salt to obtain the compound of the formula I.
2 more elements
Dependencies are inferred from the claim text.