Process to prepare 3-methyl-2-nitrobenzoic acid by air oxidation

Patent metadata

Field	Value
Publication number	US-10155718-B2
Application number	US-201715819646-A
Country	US
Kind code	B2
Filing date	Nov 21, 2017
Priority date	May 29, 2014
Publication date	Dec 18, 2018
Grant date	Dec 18, 2018

Abstract

wherein R1 is C1-C7 alkyl, C3-C6 cycloalkyl or C4-C7 alkylcycloalkyl.

First claim

The invention claimed is:

1. A method for preparing a compound of Formula 7

wherein R 1 is C 1 -C 7 alkyl, C 3 -C 6 cycloalkyl or C 4 -C 7 alkylcycloalkyl;
comprising (A) contacting a compound of Formula 2

with a reducing agent to form a compound of Formula 3

(B) contacting the compound of Formula 3
with R 2 OC(═O)Cl to form a compound of Formula 4

wherein R 2 is C 1 -C 6 alkyl or C 3 -C 6 alkenyl, each optionally substituted with up to 3 halogen and up to 1 phenyl;
(C) contacting the compound of Formula 4
with a chlorinating agent to form a compound of Formula 5

(D) contacting the compound of Formula 5
with a cyclizing agent to form a compound of Formula 6

(E) contacting the compound of Formula 6
with R 1 NH 2 to form the compound of Formula 7;
characterized by using the compound of Formula 2 as prepared by a method comprising, contacting a compound of Formula 1

with an oxidation catalyst in the presence of an oxygen source and an initiator, provided that less than 99% of a compound of Formula 1 is oxidized.

2. The method of claim 1 wherein R 1 is C 1 -C 4 alkyl or C 3 -C 6 cycloalkyl.

3. The method of claim 2 wherein R 1 is methyl, isopropyl, cyclopropyl or t-butyl.

4. The method of claim 3 wherein R 1 is methyl or t-butyl.

5. The method of claim 1 wherein R 2 is C 1 -C 4 alkyl.

6. The method of claim 5 wherein R 2 is methyl or ethyl.

7. The method of claim 6 wherein R 2 is ethyl.

8. The method of claim 1 wherein the cyclizing agent is PBr 3 .

9. The method of claim 1 wherein the chlorinating agent is HCl and H 2 O 2 .

10. A method for preparing a compound of Formula 11

wherein R 1 is C 1 -C 7 alkyl, C 3 -C 6 cycloalkyl or C 4 -C 7 alkylcycloalkyl;
comprising (A) contacting a compound of Formula 2

with an activating agent and R 1 NH 2 to form a compound of Formula 8;

(B) contacting the compound of Formula 8
with a reducing agent to form a compound of Formula 9

(C) contacting the compound of Formula 9
with a brominating agent to form a compound of Formula 10

(D) contacting the compound of Formula 10
with a cyanating agent to form the compound of Formula 11;
characterized by using the compound of Formula 2 as prepared by a method comprising, contacting a compound of Formula 1

with an oxidation catalyst in the presence of an oxygen source and an initiator, provided that less than 99% of a compound of Formula 1 is oxidized.

11. The method of claim 10 wherein R 1 is C 1 -C 4 alkyl or C 3 -C 6 cycloalkyl.

12. The method of claim 11 wherein R 1 is methyl, isopropyl, cyclopropyl or t-butyl.

13. The method of claim 12 wherein R 1 is methyl or t-butyl.

14. The method of claim 13 wherein R 1 is methyl.

15. The method of claim 14 wherein R 1 is t-butyl.

Assignees

• Fmc Corp

Inventors

• Dumas Donald J

Classifications

• C07C201/12 Primary

  by reactions not involving the formation of nitro groups · CPC title

• C07C231/02

  from carboxylic acids or from esters, anhydrides, or halides thereof by reaction with ammonia or amines · CPC title

• C07C253/14

  by reaction of cyanides with halogen-containing compounds with replacement of halogen atoms by cyano groups · CPC title

• C07C205/57

  having nitro groups and carboxyl groups bound to carbon atoms of six-membered aromatic rings of the carbon skeleton · CPC title

• C07C255/57

  containing cyano groups and carboxyl groups, other than cyano groups, bound to the carbon skeleton · CPC title