Reaction #325666

Reaction equation

sodium hypobromide

2-hydroxynicotinic acid

HCl

sodium hypobromide

Br2

sodium hypobromide

Br2

2-hydroxynicotinic acid

→

desired compound

5-bromo-2-hydroxynicotinic acid

Solvents

NaOH

NaOH

Conditions

Workup

1. 1
   Otherplaced in a 50° C.
2. 2
   workup.STIRRINGstirred
3. 3
   Temperatureof heating
4. 4
   workup.STIRRINGthen was stirred for an additional 24 h
5. 5
   TemperatureThe solution was cooled to RT
6. 6
   Otherplaced in an ice bath
7. 7
   workup.STIRRINGwhile stirring
8. 8
   OtherThe precipitate which formed
9. 9
   Filtrationwas filtered
10. 10
    Washwashed
11. 11
    Otherdried

Procedure

A solution of sodium hypobromide was made by adding Br2 (1.01 ml, 39.5 mmol, 1.1 eq) slowly over a period of 5 min to NaOH (5N, 40 ml) that was previously cooled to 0° C. in an ice bath. The solution was stirred for 10 min before adding 2-hydroxynicotinic acid (5.0 g, 35.9 mmol) and placed in a 50° C. oil bath and stirred. Concurrently, a second pot of sodium hypobromide solution was made by slowly adding Br2 (1.01 ml, 39.5 mmol, 1.1 eq) to a NaOH solution (5N, 40 ml) in an ice bath. The second pot of sodium hypobromide was added to the solution of 2-hydroxynicotinic acid after 24 h of heating then was stirred for an additional 24 h. The solution was cooled to RT, placed in an ice bath and acidified with concentrated HCl while stirring. The precipitate which formed was filtered, washed and dried to afford the desired compound as an off-white solid.

Source