Ethanolamine → Methyl 4-butyl-3,4-dihydro-2H-1,4-benzoxazine-6-carboxylate

HRID 349008

Reaction equation

HRID 349008 reaction equation
[CH2:1]([N:5]1[C:10]2[CH:11]=[C:12]([C:15]([O:17][CH3:18])=[O:16])[CH:13]=[CH:14][C:9]=2[O:8][CH2:7][C:6]1=O)[CH2:2][CH2:3][CH3:4].B1C2CCCC1CCC2.C(CN)O>O1CCCC1>[CH2:1]([N:5]1[C:10]2[CH:11]=[C:12]([C:15]([O:17][CH3:18])=[O:16])[CH:13]=[CH:14][C:9]=2[O:8][CH2:7][CH2:6]1)[CH2:2][CH2:3][CH3:4]

Participants

5

Reactant 3

HCID 700EthanolamineHCID 789669-Borabicyclo(3.3.1)nonaneHCID 21086200Methyl 4-butyl-3-oxo-3,4-dihydro-2H-1,4-benzoxazine-6-carboxylate

Product 1

HCID 21086198Methyl 4-butyl-3,4-dihydro-2H-1,4-benzoxazine-6-carboxylateYield 80.1%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

A solution of methyl 4-butyl-3-oxo-3,4-dihydro-2H-1,4-benzoxazine-6-carboxylate (800 mg) and 9-BBN (1.6 g) in tetrahydrofuran (13 mL) was refluxed for 1.5 h. The mixture was cooled to room temperature, ethanolamine (0.4 mL) was added, and the resulting solution was concentrated under reduced pressure. The residue was washed with hexanes, filtered, and the filtrate was concentrated under reduced pressure. Purification by flash column chromatography (silica, 25% ethyl acetate/hexanes) afforded 607 mg of the title compound: 1H NMR (300 MHz, DMSO-d6) δ 7.21, 7.16, 6.75, 4.24–4.21, 3.78, 3.34–3.24, 1.55–1.47, 1.38–1.30, 0.95–0.90.

Workup

  1. concentrationthe resulting solution was concentrated under reduced pressure
  2. washThe residue was washed with hexanes
  3. filtrationfiltered
  4. concentrationthe filtrate was concentrated under reduced pressure
  5. customPurification by flash column chromatography (silica, 25% ethyl acetate/hexanes)

Sources & evidence

ORD record
ord-95f9ca50e434407a8f6c89eeb4c2978d
Source dataset
uspto-grants-2007_02
Patent number
US07176242B2

Linked notes

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