Bromination of pyridine derivatives

Patent metadata

Field	Value
Publication number	US-11613549-B2
Application number	US-201916960192-A
Country	US
Kind code	B2
Filing date	Jan 14, 2019
Priority date	Jan 23, 2018
Publication date	Mar 28, 2023
Grant date	Mar 28, 2023

Abstract

The present invention relates to a process for the preparation pyridine derivatives of the formula (I).

First claim

The invention claimed is:

1. A process for preparing a compound of formula I,

in which
R 1 is in each case independently selected from hydrogen, halogen, C 1 -C 6 -alkyl and C 1 -C 6 -halogenalkyl;
R 2 is in each case independently selected from hydrogen and halogen;
R 10 is in each case independently selected from H, halogen, O(R 95 ), C 1 -C 6 -alkyl and C 1 -C 6 -halogenalkyl; wherein
R 95 is C 1 -C 6 -alkyl, C 1 -C 6 -halogenalkyl;

comprising:
(i) reacting a compound of formula II

wherein R 1 , R 2 and R 19 are as defined above with 1,3-dibromo-5,5-dimethylhydantoin (DBDMH) in the presence of oleum 65%.

2. The process according to claim 1 , wherein R 1 and R 2 are hydrogen, and R 10 is C 1 -C 6 -alkyl.

3. The process according to claim 1 , wherein R 1 and R 2 are hydrogen and R 10 is CH 3 .

4. A process for preparing 2,3-disubstituted pyridine compounds of the formula III

wherein
R 1 is in each case independently selected from hydrogen, halogen, C 1 -C 6 -alkyl and C 1 -C 6 -halogenalkyl;
R 2 is in each case independently selected from hydrogen and halogen;
R 3 , R 4 are independently selected from C 1 -C 6 -alkyl, C 2 -C 6 -alkenyl, C 2 -C 6 -alkynyl, C 1 -C 6 -halogenalkyl, C 2 -C 6 -halogenalkenyl and C 2 -C 6 -halogenalkynyl;
R 5 is halogen;
R 6 is halogen;
R 7 , R 6 together with the carbon atoms to which they are bound form a ring A, wherein the ring A is phenyl and wherein the ring A is substituent by (A 76 ) o ,
wherein
is 0, 1, 2 or 3; and
R 78 is independently selected from halogen, C 1 -C 6 -alkyl, C 1 -C 6 -alkoxy, C 1 -C 6 -halogenalkyl and C 1 -C 6 -halogenalkoxy;

R 10 is in each case independently selected from H, halogen, O(R 95 ), C 1 -C 6 -alkyl and C 1 -C 6 -halogenalkyl; wherein
R 95 is C 1 -C 6 -alkyl, C 1 -C 6 -halogenalkyl;

comprising:
(i) providing a compound of the formula I by a process according to claim 1 ;
(ii) reacting the compound of the formula I with a compound of the formula IV

in which
R 3 , R 4 , R 5 , R 6 , R 7 and R 8 are each as defined for formula III; and X is a metal ion.

5. The process according to claim 4 , wherein R 1 and R 2 are hydrogen, R 3 and R 4 is C 1 -C 6 -alkyl, R 5 and R 6 are halogen, R 7 and R 8 form a phenyl, o is 0 and R 10 is C 1 -C 6 -alkyl.

6. The process according to claim 4 , wherein R 1 and R 2 are hydrogen, R 3 and R 4 are CH 3 , R 5 and R 6 are F, R 7 and R 8 form a phenyl, o is 0 and R 10 is CH 3 .

7. The process according to claim 4 , wherein X is selected from the group consisting of Li, Na, K, and Cs.

Assignees

• Basf Se

Inventors

• Rack Michael
• Mueller Bernd

Classifications

• C07D213/61 Primary

  Halogen atoms or nitro radicals · CPC title

• C07D217/26

  Carbon atoms having three bonds to hetero atoms with at the most one bond to halogen · CPC title

• C07D401/04

  directly linked by a ring-member-to-ring-member bond · CPC title

• C07F1/02 Primary

  Lithium compounds · CPC title