Water → 6-iodo-2,2,3-trimethyl-1(2H)-benzopyran

HRID 2399309Notes

Reaction equation

HRID 2399309 reaction equation
[Br-].[CH3:2][CH:3]([O:7][C:8]1[CH:33]=[CH:32][C:31]([I:34])=[CH:30][C:9]=1[CH2:10][P+](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1)[C:4](=O)[CH3:5].[Na].[CH2:36](OCC)C.O>C(O)C>[I:34][C:31]1[CH:32]=[CH:33][C:8]2[O:7][C:3]([CH3:2])([CH3:36])[C:4]([CH3:5])=[CH:10][C:9]=2[CH:30]=1

Participants

6

Reactant 4

HCID 962WaterHCID 3283Diethyl EtherHCID 5360545SodiumHCID 867489552-(1-Methyl-2-oxo-propyloxy)-5-iodobenzyltriphenylphosphonium bromide

Product 1

HCID 193868876-iodo-2,2,3-trimethyl-1(2H)-benzopyranYield 85%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent2×

Procedure

To a suspension of 2-(1-methyl-2-oxo-propyloxy)-5-iodobenzyltriphenylphosphonium bromide (0.71 g, 0.00108 mol) in absolute ethanol (3 ml) was added dropwise at room temperature a solution of sodium (0.025 g) in absolute ethanol (1 ml). After twelve hours at room temperature, diethyl ether and water were added. The organic phase was separated, dried and evaporated. The residue was chromatographed on silica gel, eluting with a mixture of dichloromethane/heptane (50/50) to give 0.29 g (85%) of 6-iodo-2,2,3-trimethyl-1(2H)-benzopyran, as an oil, 1NMR (CDCl3): δ1.4 (s, 6H), 1.8 (s, 3H), 6.0 (s, 1H), 6.55 (d, 1H), 7.2 (d, 1H), 7.35 (d, 1H).

Workup

  1. waitAfter twelve hours at room temperature
  2. customThe organic phase was separated
  3. customdried
  4. customevaporated
  5. customThe residue was chromatographed on silica gel
  6. washeluting with a mixture of dichloromethane/heptane (50/50)

Sources & evidence

ORD record
ord-d9b897b047a54d7f83d91b92ba28da52
Source dataset
uspto-grants-1995_09
Patent number
US05447943

Reaction notes

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