Methanol → 5,6-Dihydropyrido[2,3-b][1,4]benzoxazepine

HRID 1457651Notes

Reaction equation

HRID 1457651 reaction equation
[N:1]1[C:6]2[O:7][C:8]3[CH:16]=[CH:15][CH:14]=[CH:13][C:9]=3[C:10](=O)[NH:11][C:5]=2[CH:4]=[CH:3][CH:2]=1.B.CSC.CO>O1CCCC1>[N:1]1[C:6]2[O:7][C:8]3[CH:16]=[CH:15][CH:14]=[CH:13][C:9]=3[CH2:10][NH:11][C:5]=2[CH:4]=[CH:3][CH:2]=1

Participants

5

Reactant 3

HCID 887MethanolHCID 11820483Pyrido[2,3-b][1,4]benzoxazepin-6(5H)-oneHCID 12423031(Dimethyl sulfide)trihydroboron

Product 1

HCID 220998165,6-Dihydropyrido[2,3-b][1,4]benzoxazepineYield 29.8%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

A mixture of 2.8 g of pyrido[2,3-b][1,4]benzoxazepin-6(5H)-one, 10 ml of tetrahydrofuran and 3 ml of 10M borane-dimethylsulfide in tetrahydrofuran is stirred at room temperature overnight and then refluxed for 3 hours. To the mixture is added dropwise under argon, 5 ml of methanol. The solvent is removed under vacuum and methanol added. The solvent is removed under vacuum and 12 ml of 2N NaOH added to the residue. The mixture is refluxed for 2 hours and extracted with ethyl acetate. The extract is washed with 2N citric acid, H2O, brine and dried (Na2SO4). The solution is filtered through a thin pad of hydrous magnesium silicate and the filtrate concentrated to dryness under vacuum. The residue is chromatographed on a column (2"×18") of silica gel (32° g) with hexane-ethyl acetate (1:1) as solvent to give 0.78 g of crystals, m.p. 172°-174° C.

Workup

  1. temperaturerefluxed for 3 hours
  2. additionTo the mixture is added dropwise under argon
  3. customThe solvent is removed under vacuum and methanol
  4. additionadded
  5. customThe solvent is removed under vacuum and 12 ml of 2N NaOH
  6. additionadded to the residue
  7. temperatureThe mixture is refluxed for 2 hours
  8. extractionextracted with ethyl acetate
  9. washThe extract is washed with 2N citric acid, H2O, brine
  10. dry with materialdried (Na2SO4)
  11. filtrationThe solution is filtered through a thin pad of hydrous magnesium silicate
  12. concentrationthe filtrate concentrated to dryness under vacuum
  13. customThe residue is chromatographed on a column (2"×18") of silica gel (32° g) with hexane-ethyl acetate (1:1) as solvent

Sources & evidence

ORD record
ord-55f29b6ea60848ad846c6240871851de
Source dataset
uspto-grants-1998_12
Patent number
US05849735

Reaction notes

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