HCID 12398308, compound → HCID 66912107, compound

HRID 1990856Notes

Reaction equation

HRID 1990856 reaction equation
C([O:3][C:4]([C:6]1[CH:15]=[C:14]([O:16][CH2:17][CH3:18])[C:9]2[NH:10][C:11](=[O:13])[O:12][C:8]=2[CH:7]=1)=O)C.[H-].C([Al+]CC(C)C)C(C)C>ClCCl.C1COCC1>[CH2:17]([O:16][C:14]1[C:9]2[NH:10][C:11](=[O:13])[O:12][C:8]=2[CH:7]=[C:6]([CH2:4][OH:3])[CH:15]=1)[CH3:18]

Participants

5

Reactant 2

HCID 12398308HCID 12398308, compoundHCID 21225700Diisobutylaluminumhydride

Product 1

HCID 66912107HCID 66912107, compoundYield 75%

Reagents, catalysts & solvents 2

HCID 6344DichloromethaneSolventHCID 8028TetrahydrofuranSolvent

Procedure

To a solution of 4-ethoxy-2-oxo-2,3-dihydro-benzooxazole-6-carboxylic acid ethyl ester (1.1 g, 4.38 mmol, 1.0 equiv; prepared as described in I. Kompis, A. Wick Helv. Chim. Acta 1977, 60, 3025-3034) in a mixture of dichloromethane (20 mL) and THF (10 mL) at −78° C. under Ar was slowly added diisobutylaluminium hydride (14.0 mL, 14.02 mmol, 3.2 equiv, 1 M solution in dichloromethane) over a time period of 15 min, the cooling bath removed on completion of addition and the reaction allowed to reach 0° C. After 1 h, the excess hydride was quenched by cautious addition of a sat. solution of potassium sodium tartrate (10 mL). The solidified mixture was extracted with hot THF, the combined organic phases concentrated by evaporation under reduced pressure and the crude material purified with column chromatography on silica eluting with hexane/ethyl acetate (1:2) providing 0.69 g (75%) of the title compound. 1H NMR (300 MHz, DMSO): δ 1.37 (t, J=7.0 Hz, 3H), 4.15 (q, J=7.0 Hz, 2H), 4.49 (d, J=5.6 Hz, 2H), 5.21 (t, J=5.6 Hz, 1H), 6.82 (s, 1H), 6.85 (s, 1H), 11.64 (br s, 1H). 13C NMR (75 MHz, DMSO): δ 14.61, 62.89, 64.26, 100.74, 106.46, 117.80, 137.50, 142.74, 144.05, 154.54. MS (ISP): 209.8 [M+H]+.

Workup

  1. customprepared
  2. customover a time period of 15 min
  3. customthe cooling bath removed on completion of addition
  4. customto reach 0° C
  5. customthe excess hydride was quenched by cautious addition of a sat. solution of potassium sodium tartrate (10 mL)
  6. extractionThe solidified mixture was extracted with hot THF
  7. concentrationthe combined organic phases concentrated by evaporation under reduced pressure
  8. customthe crude material purified with column chromatography on silica eluting with hexane/ethyl acetate (1:2)

Sources & evidence

ORD record
ord-fd94cf68b0284449acdebdc5387b90d5
Source dataset
uspto-grants-2010_01
Patent number
US07645753B2

Reaction notes

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