Preparation of hydrazidines

US4443629A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Gerhard Bonse · Neunburg vorm Wald, DE
• Thomas Schmidt · Neustadt, DE

Key dates

• Filing date: Jun 14, 1982
• Grant date: Apr 17, 1984
• Expiry date: Jun 14, 2002

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C257/22
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

A one-step process for the preparation of hydrazidines of the general formula ##STR1## in which R represents an optionally substituted alkyl group, an optionally substituted cycloalkyl group, an optionally substituted aryl group or an optionally substituted aralkyl group, or their acid addition salts, in high yield, comprises reacting appropriate amidines or their acid addition salts with hydrazine in solvents at reduced pressure and at temperatures between -80.degree. C. and +100.degree. C., the reaction being effected in the presence of water present in the solvent and/or in the hydrazine by employing it as hydrazine hydrate. The hydrazidines of formula (I) and their salts are valuable intermediates in heterocyclic chemistry, for example for the synthesis of herbicidally active as-triazinones.