Sulfuric Acid → 5-(2-Bromoethoxy)-2,1,3-benzothiadiazol-2-one

HRID 1955233Notes

Reaction equation

HRID 1955233 reaction equation
[NH2:1][C:2]1[CH:3]=[C:4]([CH:9]=[CH:10][C:11]=1[NH2:12])[O:5][CH2:6][CH2:7][Br:8].[O:13]=[S:14](Cl)Cl.OS(O)(=O)=O>N1C=CC=CC=1>[Br:8][CH2:7][CH2:6][O:5][C:4]1[CH:9]=[CH:10][C:11]2=[N:12][S:14](=[O:13])[N:1]=[C:2]2[CH:3]=1

Participants

5

Reactant 3

HCID 1118Sulfuric AcidHCID 24386Thionyl ChlorideHCID 232945062-(3,4-Diaminophenoxy)ethyl bromide

Product 1

HCID 232945645-(2-Bromoethoxy)-2,1,3-benzothiadiazol-2-oneYield 17%

Reagents, catalysts & solvents 1

HCID 1049PyridineSolvent

Procedure

To a cooled (ice-water) solution of 2-(3,4-diaminophenoxy)ethyl bromide (2.03 g, 8.8 mmol) in pyridine (40 mL) was added dropwise 0.65 mL (8.9 mml) of SOCl2 with stirring. The resulting mixture was stirred at r.t for 2 h, then 4N H2SO4 was added dropwise with cooling. The acidic (pH 5) mixture was extracted with CHCl3 (4×50 mL). The CHCl3 solution was washed with brine, dried (Na2SO4), then evaporated to give 420 mg (17%) of 5-(2-bromoethoxy)-2,1,3-benzothiadiazol-2-one as an orange-yellow powder. 1H NMR (CDCl3): 3.737 (t, 2H, J=6), 4.407 (t, 2H, J=6), 7.195 (d, 1H, J=2), 7.341 (dd, 1H, J=9; 2), 7.874 (d, 1H, J=9).

Workup

  1. stirringThe resulting mixture was stirred at r.t for 2 h
  2. temperaturewith cooling
  3. extractionThe acidic (pH 5) mixture was extracted with CHCl3 (4×50 mL)
  4. washThe CHCl3 solution was washed with brine
  5. dry with materialdried (Na2SO4)
  6. customevaporated

Sources & evidence

ORD record
ord-8354387191a3455ebe5f53611e866a78
Source dataset
uspto-grants-2000_09
Patent number
US06124323

Reaction notes

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