Boron tribromide → 4-Amino-5-chloro-2-hydroxybenzoic acid

HRID 973411Notes

Reaction equation

HRID 973411 reaction equation
B(Br)(Br)Br.C[O:6][C:7]1[CH:16]=[C:15]([NH2:17])[C:14]([Cl:18])=[CH:13][C:8]=1[C:9]([O:11]C)=[O:10]>C(Cl)Cl>[NH2:17][C:15]1[CH:16]=[C:7]([OH:6])[C:8](=[CH:13][C:14]=1[Cl:18])[C:9]([OH:11])=[O:10]

Participants

4

Reactant 2

HCID 25134Boron tribromideHCID 700493Methyl 4-amino-5-chloro-2-methoxybenzoate

Product 1

HCID 148832224-Amino-5-chloro-2-hydroxybenzoic acid

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

A 0.1 molar solution of boron tribromide in methylene chloride (600 ml) is added to a stirred suspension of methyl 2-methoxy-4-amino-5-chlorobenzoate (37 g) in methylene chloride (500 ml). After stirring for 20 hrs, the mixture is poured into ice water, and the precipitate remaining in the reaction container is washed in the ice water mixture with a solution of 5.5N NaOH (600 mls). The aqueous layer is separated and acidified to pH3. The resulting precipitate is filtered, washed with water and dried affording 4-amino-5-chlorosalicylic acid which is used directly in the next step.

Workup

  1. washis washed in the ice water mixture with a solution of 5.5N NaOH (600 mls)
  2. customThe aqueous layer is separated
  3. filtrationThe resulting precipitate is filtered
  4. washwashed with water
  5. customdried

Sources & evidence

ORD record
ord-e583591835fe4de4ae53c218a48d29fa
Source dataset
uspto-grants-1991_11
Patent number
US05063230

Reaction notes

Loading…