Bayer Aktiengesellschaft

Robert S&ouml;llner

Alexander Klausener

Johannes Scherer

Horst Behre

Lars Rodefeld

This invention relates to the preparation of N,N&prime;-carbonyldiazoles in a particularly advantageous manner by reacting corresponding azolide salts with phosgene in an aromatic compound or an ether as solvent. The azolide salts are preferably prepared by a novel process from an azole that is reacted with a compound of the formula M&prime;R or MgR Z&prime; in the presence of a solvent.

Process for the preparation of N,N&prime;-carbonyldiazoles and azolide salts

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 &minus;20 to &plus;30&deg; 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.

Method for preparing methyl carbazate

The invention relates to a process for the preparation of N,N&prime;-carbonyldiazoles by reacting azoles with phosgene in a solvent, whereby the azole and the phosgene are metered into an aromatic solvent dried by incipient distillation in such a way that in the time in which 1 mol of azole is metered in, from 0.17 to 0.34 mol of phosgene is metered in simultaneously.

Growing community of inventors

Leverkusen, Germany

Robert Söllner

Growing community of inventors

Leverkusen, Germany

Robert S&ouml;llner

Robert Söllner