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

US4052460A · 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: Jan 20, 1976
• Grant date: Oct 4, 1977
• Expiry date: Jan 20, 1996

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 product is a known compound suited for further syntheses.