Production of 3,3-dimethyl-2-oxo-butyric acid salt

US4898974A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Karlfried Dickore · Leverkusen, DE
• Hans D. Engels · Solingen, DE
• Hans Kratzer · Wuppertal, DE
• Walter Merz

Key dates

• Filing date: Apr 23, 1985
• Grant date: Feb 6, 1990
• Expiry date: Apr 23, 2005

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C51/00
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

Dichloropinacolone is produced by introducing into pinacolone twice the molar amount of chlorine, the exothermic reaction mass being cooled initially to maintain the temperature below about 50.degree. C. until about 60 to 80% of the chlorine has been introduced, and then heating the reaction mass to a temperature above 50.degree. C. during introducing of the remainder of the chlorine, thereby to produce dichloropinacolone, and terminating chlorine introduction when the dichloropinacolone content of the reaction mass is at least about 97%. The molten product is added to an aqueous solution of an alkali maintained at a temperature of at least about 50.degree. C., the alkali being present in more than three times the molar amount of the dichloropinacolone. To the resulting solution of a salt of 3,3-dimethyl-2-hydroxy-butyric acid, brought to a pH of about 9 to 12, there is added approximately the stoichiometric amount of potassium permanganate. Solid MnO.sub.2 precipitates out and is separated from the substantially pure dissolved salt of 3,3-dimethyl-2-oxo-butyric acid. The produce is a known compound suited for further syntheses.