Process for preparing substituted N-carbamoyl-Tetrazolinones

US5686392A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Uwe Stelzer · Burscheid, DE
• Wolfgang Gau · Wuppertal, DE
• Karl-Julius Reubke

Key dates

• Filing date: Feb 1, 1996
• Grant date: Nov 11, 1997
• Expiry date: Feb 1, 2016

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07D257/04
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

The herbicidally active substituted N-carbamoyl-tetrazolinones of the formula (I) ##STR1## in which R.sup.1 represents, inter alia, an (optionally substituted) phenyl radical, PA1 R.sup.2 represents, inter alia, an alkyl radical, and PA1 R.sup.3 represents, inter alia, a cycloalkyl radical, are obtained in very good yields and at high purity--i.e. free from the isomeric O-carbamoyloxytetrazoles (Ia)--by reacting tetrazolinones of the formula (II) with carbamoyl halides of the formula (III) (X=halogen) ##STR2## in the presence of an acid acceptor and in the presence of a diluent, at temperatures of between 0.degree. C. and 200.degree. C., and either isomerizing the O-carbamoylation product of the formula (Ia), which is formed under these circumstances as a byproduct, into the desired product of the formula (I) by heating, or else converting it by hydrolysis or alcoholysis into water-soluble, and thus readily separable, components (variable (a)). Three variants (b), (c) and (d) which are closely related to this process (a) are also described: PA1 Process variant (b) proceeds in analogy with (a) but via the (novel, isolated) metal salts (IIa) of the tetrazolinones (II). In variant (c)…