Bromine → 7-Bromo-1,3-benzothiazol-2-amine

HRID 2077514Notes

Reaction equation

HRID 2077514 reaction equation
[Br:1][C:2]1[CH:3]=[C:4]([NH:8][C:9]([NH2:11])=[S:10])[CH:5]=[CH:6][CH:7]=1.BrBr.BrC1C=CC2N=C(N)SC=2C=1>CC#N.C(O)(=O)C>[Br:1][C:2]1[C:3]2[S:10][C:9]([NH2:11])=[N:8][C:4]=2[CH:5]=[CH:6][CH:7]=1

Participants

6

Reactant 3

HCID 24408BromineHCID 851492-Benzothiazolamine, 6-bromo-HCID 27356191-(3-bromophenyl)thiourea

Product 1

HCID 203571127-Bromo-1,3-benzothiazol-2-amineYield 101.7%

Reagents, catalysts & solvents 2

HCID 176Acetic AcidSolventHCID 6342AcetonitrileSolvent

Procedure

1-(3-Bromophenyl)-2-thiourea (Oakwood Products, Inc., West Columbia, S.C.; 2.479 g, 10.73 mmol) was suspended in MeCN (200 mL) and cooled in an ice water bath under nitrogen. Then, a solution of bromine (1.1 mL, 21 mmol) in acetic acid (10 mL) was added dropwise over 15 minutes. The reaction was stirred while being cooled in an ice water bath for 30 minutes, then allowed to warm to RT while stirring over the weekend. The resulting precipitate was filtered and the solid was washed with Et2O to afford the mixture (2.5 g, 100% yield) of 7-bromobenzo[d]thiazol-2-amine and 6-bromobenzo[d]thiazol-2-amine in a 1:2 ratio. MS (ESI pos. ion) m/z: 229 (MH+, 79Br), 231 (MH+, 81Br). Calculated exact mass for C7H5BrN2S: 228 (79Br), 230 (81Br).

Workup

  1. temperaturecooled in an ice water bath under nitrogen
  2. temperaturewhile being cooled in an ice water bath for 30 minutes
  3. stirringwhile stirring over the weekend
  4. filtrationThe resulting precipitate was filtered
  5. washthe solid was washed with Et2O

Sources & evidence

ORD record
ord-bfa18956a12345eda5b07c4780192c42
Source dataset
uspto-grants-2011_04
Patent number
US07928140B2

Reaction notes

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