Bromine → 4-Bromo-1,3-benzothiazol-5-amine

HRID 1936593Notes

Reaction equation

HRID 1936593 reaction equation
[NH2:1][C:2]1[CH:3]=[CH:4][C:5]2[S:9][CH:8]=[N:7][C:6]=2[CH:10]=1.[Br:11]Br>C(Cl)(Cl)Cl.[OH-].[NH4+].C(Cl)Cl>[NH2:1][C:2]1[CH:3]=[CH:4][C:5]2[S:9][CH:8]=[N:7][C:6]=2[C:10]=1[Br:11]

Participants

6

Reactant 2

HCID 24408BromineHCID 70749Benzothiazol-5-amine

Product 1

HCID 224622234-Bromo-1,3-benzothiazol-5-amineYield 79.2%

Reagents, catalysts & solvents 3

HCID 6212ChloroformSolventHCID 6344DichloromethaneSolventHCID 14923Ammonium HydroxideSolvent

Procedure

To a cooled (5° C.) solution of 2.04 g of 5-aminobenzothiazole in 60 mL of chloroform are added dropwise 2.15 g of bromine while maintaining the temperature below 10° C. After completion of the addition, the reaction mixture is stirred for 30 minutes at room temperature, then diluted with 14 mL of concentrated ammonium hydroxide and 16 mL of methylene chloride. The aqueous layer is washed with methylene chloride (2×16 mL) and the combined organic layers are rotary evaporated. The residue is purified by an aspirator vacuum-filtration through silica gel, eluting with 15% to 30 ethyl acetate in hexanes to provide 2.44 g of 5-amino-4-bromobenzothiazole as a reddish solid.

Workup

  1. temperaturewhile maintaining the temperature below 10° C
  2. additionAfter completion of the addition
  3. washThe aqueous layer is washed with methylene chloride (2×16 mL)
  4. filtrationThe residue is purified by an aspirator vacuum-filtration through silica gel
  5. washeluting with 15% to 30 ethyl acetate in hexanes

Sources & evidence

ORD record
ord-64f03ef091e041e194fa703f48669c6e
Source dataset
uspto-grants-2002_05
Patent number
US06391878B2

Reaction notes

Loading…