Hydrogen Bromide → 6-Bromo-1,3-dihydro-2-benzofuran-1-one

HRID 2420897Notes

Reaction equation

HRID 2420897 reaction equation
N([O-])=O.[Na+].N[C:6]1[CH:14]=[C:13]2[C:9]([CH2:10][O:11][C:12]2=[O:15])=[CH:8][CH:7]=1.[BrH:16]>O>[Br:16][C:6]1[CH:14]=[C:13]2[C:9]([CH2:10][O:11][C:12]2=[O:15])=[CH:8][CH:7]=1

Participants

5

Reactant 3

HCID 260Hydrogen Bromide2×HCID 936316-AminophthalideHCID 23668193Sodium Nitrite

Product 1

HCID 2622356-Bromo-1,3-dihydro-2-benzofuran-1-oneYield 84%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent2×

Procedure

A solution of NaNO2 (2.2 g, 0.040 mol) in H2O (22 mL) was added to a mixture of 6-aminoisobenzofuran-1(3H)-one (5.0 g, 0.030 mol) in HBr (70 mL, 48%) over 5 min at 0° C. The mixture was stirred for 20 minutes and was then pipetted into an ice cold solution of CuBr (22.0 g, 0.210 mol) in HBr (48%, 23 mL). The resulting dark brown mixture was stirred for 20 min and was then diluted with H2O (200 mL) to produce an orange precipitate. The precipitate was filtered off and was treated with saturated NaHCO3. The mixture was extracted with ethyl acetate (20 mL×3). The organic layer was dried over Na2SO4 and evaporated in vacuo to give 6-bromoisobenzofuran-1(3H)-one (5.4 g, 84%). 1H NMR (300 MHz, CDCl3) □ 8.05 (d, J=1.8, 1H), 7.80 (dd, J=8.1, 1.8, 1H), 7.39 (d, J=8.1, 1H), 5.28 (s, 2H).

Workup

  1. stirringThe resulting dark brown mixture was stirred for 20 min
  2. customto produce an orange precipitate
  3. filtrationThe precipitate was filtered off
  4. additionwas treated with saturated NaHCO3
  5. extractionThe mixture was extracted with ethyl acetate (20 mL×3)
  6. dry with materialThe organic layer was dried over Na2SO4
  7. customevaporated in vacuo

Sources & evidence

ORD record
ord-f64a218ca7bc4054933d03d4fcb450c5
Source dataset
uspto-grants-2011_06
Patent number
US07956052B2

Reaction notes

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