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

HRID 2073996Notes

Reaction equation

HRID 2073996 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 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. stirringAfter stirring for 20 hrs
  2. washis washed in the ice water mixture with a solution of 5.5N NaOH (600 mls)
  3. customThe aqueous layer is separated
  4. filtrationThe resulting precipitate is filtered
  5. washwashed with water
  6. customdried

Sources & evidence

ORD record
ord-c3ad9eb49c464366b04c412fb893fc04
Source dataset
uspto-grants-1990_04
Patent number
US04920219

Reaction notes

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