The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 28, 1978
Filed:
May. 25, 1977
Labaz, Paris, FR;
Abstract
Process for the preparation of di-n-propyl acetic acid of formula: ##STR1## and its non-toxic alkali and alkaline earth metal salts whereby in a single stage, sodium n-propylate in n-propanol medium is added to a reaction medium formed of a cyanacetic ester of general formula: ##STR2## in which R represents an alkyl radical having from 1 to 4 carbon atoms, and n-propyl bromide or iodide, the alkylation reaction taking place under reflux, the crude ester obtained is saponified with a 10 to 20% solution of sodium or potassium hydroxide, the salt thus obtained is acidified with a strong acid, to give the crude di-n-propyl cyanacetic acid, which is decarboxylated by heating at a temperature between 140.degree. and 190.degree. C, to provide the di-n-propyl acetonitrile, the di-n-propyl acetonitrile obtained is hydrolysed by means of an aqueous solution of 75 to 80% sulphuric acid at a temperature of 80.degree.-140.degree. C to give the crude di-n-propyl acetamide, which is hydrolyzed by means of an aqueous solution of 75-80% sulphuric acid at a temperature of 40.degree.-80.degree. C in the presence of sodium nitrite, to provide di-n-propyl acetic acid, which is caused to react, if so desired, with an alkali metal hydroxide or alkaline earth metal oxide in order to obtain the corresponding salt.