Iodine → 1,6-Dihydro-2,3-dimethyl-6-(4-methylphenyl)-1-phenoxycarbonyl pyridine

HRID 22259

Reaction equation

HRID 22259 reaction equation
Br[C:2]1[CH:7]=[CH:6][C:5]([CH3:8])=[CH:4][CH:3]=1.[Mg].II.[N:12]1[CH:17]=[CH:16][CH:15]=[C:14]([CH3:18])[C:13]=1[CH3:19].Cl[C:21]([O:23][C:24]1[CH:29]=[CH:28][CH:27]=[CH:26][CH:25]=1)=[O:22]>O1CCCC1>[CH3:19][C:13]1[N:12]([C:21]([O:23][C:24]2[CH:29]=[CH:28][CH:27]=[CH:26][CH:25]=2)=[O:22])[CH:17]([C:2]2[CH:7]=[CH:6][C:5]([CH3:8])=[CH:4][CH:3]=2)[CH:16]=[CH:15][C:14]=1[CH3:18]

Participants

7

Reactant 5

HCID 807IodineHCID 78054-BromotolueneHCID 114202,3-LutidineHCID 15891Phenyl chloroformateHCID 5462224Magnesium

Product 1

HCID 194303781,6-Dihydro-2,3-dimethyl-6-(4-methylphenyl)-1-phenoxycarbonyl pyridine

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent3×

Conditions

Temperature
-60 °C

Procedure

A solution of p-bromotoluene (13.5 g) in 50 ml of tetrahydrofuran was added to magnesium (1.5 g) and 1 crystal of iodine in a little tetrahydrofuran, and the mixture was refluxed for 1 hour. In a separate flask, a solution of 2,3-lutidine (6.5 g) in 100 ml of tetrahydrofuran was cooled to about -60° C., and the magnesium complex prepared above added, followed by phenyl chloroformate (8 ml). The mixture was stirred for 1 hour at -60° C., then at room temperature overnight. The solvent was removed under reduced pressure, the residue partitioned between ether and 200 ml of 20% ammonium chloride, the organic layer washed with water, followed by dilute hydrochloric acid. The solvent was evaporated under reduced pressure, and the residue flash-chromatographed on silica gel, eluting with 1% ethyl acetate in heptane, to yield 12.4 g of 1,6-dihydro-2,3-dimethyl-6-(4-methylphenyl)-1-phenoxycarbonyl pyridine, m.p. 106° C.

Workup

  1. temperaturethe mixture was refluxed for 1 hour
  2. customthe magnesium complex prepared
  3. additionabove added
  4. customat room temperature
  5. customovernight
  6. customThe solvent was removed under reduced pressure
  7. customthe residue partitioned between ether and 200 ml of 20% ammonium chloride
  8. washthe organic layer washed with water
  9. customThe solvent was evaporated under reduced pressure
  10. customthe residue flash-chromatographed on silica gel
  11. washeluting with 1% ethyl acetate in heptane

Sources & evidence

ORD record
ord-0e92e498393445779a9f494f3924bc02
Source dataset
uspto-grants-1995_06
Patent number
US05428037

Linked notes

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