Preparation of nitrobenzoic and anthranilic acids

• US 5,198,575 A
• Filed: 07/13/1992
• Issued: 03/30/1993
• Est. Priority Date: 08/27/1991
• Status: Expired due to Fees

• Current Assignee: BASF AG (BASF SE)
• Original Assignee: BASF AG (BASF SE)
• Inventors: Dupuis, Jacques, Hagen, Helmut
• Primary Examiner(s): Shippen, Michael L.
• Application Number:
  US07/912,196
• Time in Patent Office: 260 Days
• Field of Search: 562/410, 562/456
• US Class Current: 562/410
• CPC Class Codes: C07C 201/12 by reactions not involving the formation of nitro groups
• CPC Class Codes: C07C 205/57 having nitro groups and carboxyl groups bound to carbon atoms of six-membered aromatic rings of the carbon skeleton
• CPC Class Codes: C07C 205/58 the carbon skeleton being further substituted by halogen atoms
• CPC Class Codes: C07C 227/04 Formation of amino groups in compounds containing carboxyl groups
• CPC Class Codes: C07C 229/56 with amino and carboxyl groups bound in ortho-position

Abstract

Nitrobenzoic acids I ##STR1## (X¹, X² =fluorine, chlorine, bromine, hydrogen or nitro) are prepared by oxidizing the corresponding nitrotoluene II ##STR2## with nitric acid in the presence of sulfuric acid and vanadium(V) compounds, and anthranilic acids III ##STR3## (Y¹, Y² =fluorine, chlorine, bromine, hydrogen or amino) are prepared from the nitrobenzoic acids I by reduction.

Claims

1. A process for preparing nitrobenzoic acids of the general formula I ##STR10## where X¹ and X² are each fluorine, chlorine, bromine, hydrogen or nitro, by oxidizing the corresponding nitrotoluene of the general formula II ##STR11## with nitric acid, which comprises carrying out the oxidation in the presence of sulfuric acid and vanadium(V) compounds.

2. A process for preparing anthranilic acids of the general formula III ##STR12## where Y¹ and Y² are each fluorine, chlorine, bromine, hydrogen or amino, by oxidizing the corresponding nitrotoluene of the general formula II ##STR13## where X¹ and X² are each fluorine, chlorine, bromine, hydrogen or nitro, with nitric acid to obtain nitrobenzoic acid of the general formula I ##STR14## and isolating and subsequently reducing this nitrobenzoic acid, which comprises carrying out the oxidation in the presence of sulfuric acid and vanadium(V) compounds.