6-Bromo-2,2,3-trimethyl-2H-benzo[b]pyran → HCID 19386902, compound

HRID 2399310Notes

Reaction equation

HRID 2399310 reaction equation
Br[C:2]1[CH:3]=[CH:4][C:5]2[O:10][C:9]([CH3:12])([CH3:11])[C:8]([CH3:13])=[CH:7][C:6]=2[CH:14]=1.[F:15][C:16]([F:21])([F:20])C([O-])=O.[K+]>CN(C)C=O.C1(C)C=CC=CC=1>[F:15][C:16]([F:21])([F:20])[C:2]1[CH:3]=[CH:4][C:5]2[O:10][C:9]([CH3:12])([CH3:11])[C:8]([CH3:13])=[CH:7][C:6]=2[CH:14]=1

Participants

5

Reactant 2

HCID 149560896-Bromo-2,2,3-trimethyl-2H-benzo[b]pyranHCID 23662811Potassium trifluoroacetate

Product 1

HCID 19386902HCID 19386902, compoundYield 51.8%

Reagents, catalysts & solvents 2

HCID 1140TolueneSolvent2×HCID 6228DimethylformamideSolvent

Procedure

A suspension containing 6-bromo-2,2,3-trimethyl-2H-1-benzopyran (38.0 g, 0.15 mol), potassium trifluoroacetate (62.0 g, 0.408 mol) and cuprous iodide (57.0 g, 0.30 mol) in dimethylformamide (530 ml) and toluene (225 ml) was heated under nitrogen until a total of 70 ml of toluene was collected by distillation. Toluene was distilled off until the temperature of the reaction mixture reached 149° C. After a further four hours at this temperature the mixture was cooled to room temperature, water and diethyl ether were added, and the organic phase separated and evaporated under reduced pressure. The residue was chromatographed on silica gel, eluting with heptane to give 18.82 g of 6-trifluoromethyl-2,2,3-trimethyl-2H-1-benzopyran as an oil, ms 242 (M+).

Workup

  1. distillationwas collected by distillation
  2. distillationToluene was distilled off until the temperature of the reaction mixture
  3. customreached 149° C
  4. additionwater and diethyl ether were added
  5. customthe organic phase separated
  6. customevaporated under reduced pressure
  7. customThe residue was chromatographed on silica gel
  8. washeluting with heptane

Sources & evidence

ORD record
ord-2a92280a1978434db71148db3342ea0f
Source dataset
uspto-grants-1995_09
Patent number
US05447943

Reaction notes

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