Process for the preparation of 4,6-dichloropyrimidines

US5677453A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Gunther Cramm · Leverkusen, DE
• Volker Kass · Leverkusen, DE
• Guido Steffan · Odenthal, DE

Key dates

• Filing date: Aug 19, 1996
• Grant date: Oct 14, 1997
• Expiry date: Aug 19, 2016

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07D239/30
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

4,6-Dichloropyrimidines are obtained by the reaction of 4,6-dihydroxypyrimidines with excess phosphoryl chloride in a particularly advantageous manner when no base is added, during and/or after the reaction 0.75 to 1.5 mol of phosphorus trichloride and 0.7 to 1.3 mol of chlorine are added per equivalent of exchanged hydroxyl groups so that an excess of phosphorus trichloride with respect to chlorine is always present, and finally phosphorus trichloride and phosphoryl chloride are separated off. This process can be carried out in a particularly simple manner and also continuously.