Method for preparing methyl carbazate

US6465678B1 · kind B1 · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Lars Rodefeld · Leverkusen, DE
• Horst Behre · Odenthal, DE
• Alexander Klausener · Neunburg vorm Wald, DE
• Robert Sollner · Jenbach, AT

Key dates

• Filing date: Jul 20, 2001
• Grant date: Oct 15, 2002
• Expiry date: Jul 20, 2021

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C281/02
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

Methyl carbazate which is particularly pure and has a particularly low tendency toward discoloration is obtained from hydrazine and dimethyl carbonate if the two reactants are metered simultaneously into an initially introduced first solvent at from −20 to +30° C., the solvent and low-boiling components are then distilled off under reduced pressure, and then either a second solvent is added to the crude methyl carbazate present and this solvent is distilled off under reduced pressure or an inert gas is passed through the crude methyl carbazate present.