Methanol → 6-Bromo-7-methoxychroman-2-one

HRID 1620024Notes

Reaction equation

HRID 1620024 reaction equation
[Br:1][C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][C:11]=1[OH:12])[O:8][C:7](=[O:13])[CH2:6][CH2:5]2.N(C(OCC)=O)=N[C:16](OCC)=O.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.CO>C1COCC1.ClCCl.O>[Br:1][C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][C:11]=1[O:12][CH3:16])[O:8][C:7](=[O:13])[CH2:6][CH2:5]2

Participants

8

Reactant 4

HCID 887MethanolHCID 11776TriphenylphosphineHCID 220568ethyl N-ethoxycarbonyliminocarbamateHCID 468354166-Bromo-7-hydroxychroman-2-one

Product 1

HCID 668766776-Bromo-7-methoxychroman-2-oneYield 56.7%

Reagents, catalysts & solvents 3

HCID 962WaterSolventHCID 6344DichloromethaneSolventHCID 8028TetrahydrofuranSolvent

Procedure

A solution of Intermediate 2 (5.0 g) in THF (20 ml) was added with diethyl azodicarboxylate (4.1 g, Ald), triphenylphosphine (8.0 g, WAKO), and methanol (990 μl, KANTO), and stirred for 4 hours. The reaction mixture was added with water (100 ml) and dichloromethane (20 ml×2) and extracted, the organic layer was successively washed with saturated aqueous sodium hydrogencarbonate, saturated aqueous ammonium chloride, and saturated brine, and dried, and the solvent was evaporated under reduced pressure. The residue was purified by column chromatography (Yamazen, n-hexane:ethyl acetate=3:1) to obtain the title compound (3.0 g).

Workup

  1. extractionextracted
  2. washthe organic layer was successively washed with saturated aqueous sodium hydrogencarbonate, saturated aqueous ammonium chloride, and saturated brine
  3. customdried
  4. customthe solvent was evaporated under reduced pressure
  5. customThe residue was purified by column chromatography (Yamazen, n-hexane:ethyl acetate=3:1)

Sources & evidence

ORD record
ord-1eac9f34549a47af8336470582f14a9a
Source dataset
uspto-grants-2014_07
Patent number
US08772327B2

Reaction notes

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