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

HRID 1665784Notes

Reaction equation

HRID 1665784 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 before it was pipetted into an ice cold solution of CuBr (22 g, 0.21 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, treated with sat. NaHCO3 solution, and extracted with EtOAc (20 mL×3). The organics were dried over Na2SO4 and evaporated in vacuo to give 6-bromoisobenzofuran-1(3H)-one (5.4 g, 84%). 1H NMR (300 MHz, CDCl3) δ 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. additiontreated with sat. NaHCO3 solution
  5. extractionextracted with EtOAc (20 mL×3)
  6. dry with materialThe organics were dried over Na2SO4
  7. customevaporated in vacuo

Sources & evidence

ORD record
ord-82c0e5afe3cb493e83740723ea5c9673
Source dataset
uspto-grants-2011_10
Patent number
US08039491B2

Reaction notes

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