Process for the preparation of 3-hydroxypicolinic acids

1. A process for the preparation of the compound of Formula A

wherein R 2 is a C 1 -C 4 alkyl;

which comprises the following steps:

a) creating a mixture by adding a brominating agent and water to the compound of Formula B

wherein X is Cl or Br, and R 2 is a C 1 -C 4 alkyl; and

b) isolating the compound of Formula A from the mixture.

2. The process of claim 1 wherein the brominating agent is bromine.

3. The process of claim 1 further including a base.

4. A process for the preparation of the compound of Formula B

wherein X is Cl or Br, and R 2 is a C 1 -C 4 alkyl;

which comprises the following steps:

a) creating a first mixture by combining together an O-alkylhydroxylamine hydrohalide salt of Formula I, a base, and a compound of Formula C and heating the first mixture

wherein X is Cl or Br, and R 3 is a C 1 -C 4 alkyl;

b) isolating a compound of Formula D from the first mixture

wherein R 3 is a C 1 -C 4 alkyl;

c) mixing a compound of Formula D with an alcohol and an acid compound or acid forming compound and heating to form a second mixture;

d) isolating a compound of Formula E from the second mixture

wherein R 2 and R 3 are independently a C 1 -C 4 alkyl;

e) adding a reducing agent to the compound of Formula E to form a third mixture;

f) isolating a compound of Formula F from the third mixture

wherein R 2 is a C 1 -C 4 alkyl;

g) adding a hydrohalide acid to the compound of Formula F to form a fourth mixture; and

h) isolating the compound of Formula B from the fourth mixture.

5. The process of claim 4 wherein the reducing agent is zinc metal.

6. The process of claim 4 wherein the hydrohalide acid is selected from hydrochloric acid and hydrobromic acid.

7. A process for the preparation of the compound of Formula B

wherein X is Cl or Br, and R 2 is a C 1 -C 4 alkyl;

which comprises the following steps:

a) creating a first mixture by combining together furan, a Lewis acid and a compound of Formula G

wherein R 2 is a C 1 -C 4 alkyl and R 4 is an acid cleavable group selected from an allyl, a benzyl or a substituted allyl or benzyl group;

b) isolating a compound of Formula H from the first mixture

wherein R 2 and R 4 are as defined in step a);

c) adding a strong acid to the compound of Formula H to form a second mixture; and

d) isolating the compound of Formula B from the second mixture.

8. The process of claim 7 wherein the Lewis acid is boron trifluoride etherate.

9. The process of claim 7 wherein the acid cleavable group is a benzyl group.

10. The process of claim 7 wherein the strong acid is selected from hydrochloric acid and hydrobromic acid.

11. A compound consisting of:

wherein R 2 is a C 1 -C 4 alkyl.