Ammonia → 2-Amino-5,7-dibromobenzothiazole

HRID 447003Notes

Reaction equation

HRID 447003 reaction equation
[Br:1][C:2]1[CH:3]=[C:4]([NH:9][C:10]([NH2:12])=[S:11])[CH:5]=[C:6]([Br:8])[CH:7]=1.BrBr.N>C(Cl)(Cl)Cl.O>[Br:1][C:2]1[CH:7]=[C:6]([Br:8])[C:5]2[S:11][C:10]([NH2:12])=[N:9][C:4]=2[CH:3]=1

Participants

6

Reactant 3

HCID 222AmmoniaHCID 24408BromineHCID 20157487HCID 20157487, compound

Product 1

HCID 578136892-Amino-5,7-dibromobenzothiazoleYield 100.4%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6212ChloroformSolvent

Conditions

Temperature
2.5 °C

Procedure

To a solution of (3,5-dibromo-phenyl)-thiourea (35 g, 0.11 mol) in CHCl3 (600 mL) at −55-60° C. was added dropwise a solution of Br2 (40.40 g, 0.25 mol, in 100 ml of CHCl3) over a period of 1 h. The reaction mixture was stirred at −55-60° C. for 15 min followed by refluxing at 70-75° C. for 3 h. The reaction mixture was cooled to room temperature and filtered to get the crude residue that was washed with hexane and diethyl ether. The solid thus obtained was dissolved in H2O, basified with aqueous ammonia solution to pH 10-12 and stirred for 30 min. The solid thus obtained was filtered and washed with water to get the desired product (34.0 g, 98%).

Workup

  1. temperatureby refluxing at 70-75° C. for 3 h
  2. temperatureThe reaction mixture was cooled to room temperature
  3. filtrationfiltered
  4. customto get the crude residue that
  5. washwas washed with hexane and diethyl ether
  6. customThe solid thus obtained
  7. stirringstirred for 30 min
  8. customThe solid thus obtained
  9. filtrationwas filtered
  10. washwashed with water

Sources & evidence

ORD record
ord-bffaf345c6d0411fb7673bac8cd3cc57
Source dataset
uspto-grants-2013_07
Patent number
US08481544B2

Reaction notes

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