Process for the manufacture of phosphoric acid-tris-(dimethylamide)

US4094902A · kind A · utility

Assignee

• Wacker Chemie AG · DE

Inventors

• Heinz Liberda
• Hellmuth Spes · Burghausen, DE
• Alfred Trommet

Key dates

• Filing date: Dec 6, 1976
• Grant date: Jun 13, 1978
• Expiry date: Dec 6, 1996

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07F9/224
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

Process for the manufacture of phosphoric acid-tris-(dimethylamide) (C) by reacting phosphorus oxychloride and dimethylamine in a molar ratio of 1 to at least 3, under anhydrous conditions and, optionally, under the application of pressure, which comprises carrying out the reaction in two separate process stages, wherein, in the first stage the phosphorus oxychloride and dimethylammonium chloride are heated in a molar ratio of approximately 1 : 1.5, and in the second stage dimethylamine is added to a mixture containing about 1.5 gram atoms of chlorine bonded to phosphorus and consisting of phosphoric acid dimethylamide-dichloride (A) and phosphoric acid-bis-(dimethylamide)-chloride (B) in which the proportion of (A) is not more than 50 mole %, or added to B alone, C is separated off at the end of the amine absorption and the formed dimethylammonium chloride is returned to the first stage. The compound C produced is a valuable polar solvent and reaction medium with catalytic properties which is being used increasingly as an intermediate product.