Phosphorus oxychloride → [2-Methyl-7,8-dihydro[1,4]dioxino[2,3-g][1,3]benzoxazol-8-yl]methanol

HRID 28468Notes

Reaction equation

HRID 28468 reaction equation
[OH:1][C:2]1[C:11]2[O:10][C@@H:9]([CH2:12][OH:13])[CH2:8][O:7][C:6]=2[CH:5]=[CH:4][C:3]=1C(=NO)C.P(Cl)(Cl)(Cl)=O.C([O-])(=O)C.[Na+].C[N:29](C)[C:30](=O)[CH3:31].C(#N)C>>[CH3:31][C:30]1[O:1][C:2]2[C:11]3[O:10][CH:9]([CH2:12][OH:13])[CH2:8][O:7][C:6]=3[CH:5]=[CH:4][C:3]=2[N:29]=1

Participants

5

Reactant 4

HCID 24813Phosphorus oxychlorideHCID 517045Sodium AcetateHCID 21187609acetonitrile N,N-dimethylacetamide2×HCID 1363585271-[(3S)-5-hydroxy-3-(hydroxymethyl)-2,3-dihydro-1,4-benzodioxin-6-yl]-1-ethanone oxime

Product 1

HCID 21892056[2-Methyl-7,8-dihydro[1,4]dioxino[2,3-g][1,3]benzoxazol-8-yl]methanol

Procedure

3.03 g (12.6 mmole) of 1-[(3S)-5-hydroxy-3-(hydroxymethyl)-2,3-dihydro-1,4-benzodioxin-6-yl]-1-ethanone oxime was dissolved in- a mixture of 1:3 N,N-dimethylacetamide/acetonitrile (100 mL). The solution was cooled in an ice/water bath and a solution of phosphorus oxychloride (1.26 mL, 35 mmole) in 1:3 N,N-dimethylacetamide/acetonitrile (30 mL) was added. The reaction mixture was stirred under nitrogen over a period of 48 hours. It was then added to an ice cold, saturated solution of sodium acetate, extracted with ethyl acetate, dried over magnesium sulfate, filtered and evaporated in vacuum. The resulting crude oil was column chromatographed on silica gel with 60% hexane/ethyl acetate to remove impurities and the product eluted with 40% hexane/ethyl acetate. After evaporation of the solvent in vacuum, 2.08 g (75%) of the (S)-enantiomer of the title compound was obtained as a white solid, m.p. 120° C. MS (ESI) m/z 222 (M+H)+.

Workup

  1. temperatureThe solution was cooled in an ice/water bath
  2. extractionextracted with ethyl acetate
  3. dry with materialdried over magnesium sulfate
  4. filtrationfiltered
  5. customevaporated in vacuum
  6. customchromatographed on silica gel with 60% hexane/ethyl acetate
  7. customto remove impurities
  8. washthe product eluted with 40% hexane/ethyl acetate
  9. customAfter evaporation of the solvent in vacuum, 2.08 g (75%) of the (S)-enantiomer of the title compound
  10. customwas obtained as a white solid, m.p. 120° C

Sources & evidence

ORD record
ord-ed36b1704da34938be2e9b78cb4f9983
Source dataset
uspto-grants-2008_09
Patent number
US07419986B2

Reaction notes

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