1,2-Dibromoethane → 8-Fluoro-2,3-dihydro-1,4-benzodioxin-6-carboxaldehyde

HRID 253301Notes

Reaction equation

HRID 253301 reaction equation
[F:1][C:2]1[CH:3]=[C:4]([CH:7]=[C:8]([OH:11])[C:9]=1[OH:10])[CH:5]=[O:6].C(=O)([O-])[O-].[Cs+].[Cs+].Br[CH2:19][CH2:20]Br>CN(C=O)C.ClCCl>[F:1][C:2]1[C:9]2[O:10][CH2:19][CH2:20][O:11][C:8]=2[CH:7]=[C:4]([CH:5]=[O:6])[CH:3]=1

Participants

6

Reactant 3

HCID 78391,2-DibromoethaneHCID 10796Cesium carbonateHCID 5936643-Fluoro-4,5-dihydroxybenzaldehyde

Product 1

HCID 574231098-Fluoro-2,3-dihydro-1,4-benzodioxin-6-carboxaldehydeYield 87%

Reagents, catalysts & solvents 2

HCID 6228DimethylformamideSolventHCID 6344DichloromethaneSolvent

Conditions

Temperature
80 °C

Procedure

3-fluoro-4,5-dihydroxybenzaldehyde (0.9 g; 5.7 mmol) and cesium carbonate (4.6 g; 14.2 mmol) were stirred in DMF (15 ml) at room temperature for 15 min. 1,2 Dibromoethane (638 μl; 7.4 mmol) was added and reaction mixture was stirred at 80° C. for 2.5 h and then diluted with dichloromethane (100 ml). The mixture was washed with water (2×50 ml), 10% aqueous citric acid (50 ml), brine (50 ml), dried over sodium sulfate and evaporated to dryness to yield 8-fluoro-2,3-dihydro-1,4-benzodioxine-6-carbaldehyde (0.9 g; 87% yield). 1H NMR (400 MHz, CD3OD) δ 9.74 (d, 1H), 7.25 (m, 2H), 4.37 (m, 4H).

Workup

  1. customreaction mixture
  2. washThe mixture was washed with water (2×50 ml), 10% aqueous citric acid (50 ml), brine (50 ml)
  3. dry with materialdried over sodium sulfate
  4. customevaporated to dryness

Sources & evidence

ORD record
ord-fc8e19984b994311bf0049ca2940eb24
Source dataset
uspto-grants-2011_01
Patent number
US07872014B2

Reaction notes

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