Diethyl Ether → 3-(3-{[Tert butyl(dimethyl)silyl]oxy}propyl)-2-oxo-2,3-dihydro-1,3-benzoxazole-6-carbaldehyde

HRID 590411Notes

Reaction equation

[O:1]=[C:2]1[NH:6][C:5]2[CH:7]=[CH:8][C:9]([CH:11]=[O:12])=[CH:10][C:4]=2[O:3]1.C(=O)([O-])[O-].[K+].[K+].Br[CH2:20][CH2:21][CH2:22][O:23][Si:24]([C:27]([CH3:30])([CH3:29])[CH3:28])([CH3:26])[CH3:25].CCOCC>CN(C=O)C>[Si:24]([O:23][CH2:22][CH2:21][CH2:20][N:6]1[C:5]2[CH:7]=[CH:8][C:9]([CH:11]=[O:12])=[CH:10][C:4]=2[O:3][C:2]1=[O:1])([C:27]([CH3:28])([CH3:29])[CH3:30])([CH3:26])[CH3:25]

Participants

Conditions

Temperature: 75 °C

Procedure

To a solution of 2-oxo-2,3-dihydro-1,3-benzoxazole-6-carbaldehyde (Intermediate 7, 300 mg, 1.84 mmol) in DMF (10 mL) were added potassium carbonate (633 mg, 4.58 mmol) and (3-bromopropoxy)(tert-butyl)dimethylsilane (0.47 mL, 2.03 mmol), and the resulting mixture was heated to 75° C. Upon complete disappearance of starting material (ca 16 hours), the solvent was removed under reduced pressure and the solid residue was treated with CH2Cl2 and stirred for 5 min. The suspension was filtered through Celite® and the solid residue washed with additional CH2Cl2. The filtrate was concentrated to dryness and the crude was purified by column chromatography over silica gel, eluting with Hexane:Et2O (from 0 to 32% of Et2O) to give the title compound as a white solid (550 mg, 89% yield).

Workup

customUpon complete disappearance of starting material (ca 16 hours), the solvent was removed under reduced pressure
additionthe solid residue was treated with CH2Cl2
filtrationThe suspension was filtered through Celite®
washthe solid residue washed with additional CH2Cl2
concentrationThe filtrate was concentrated to dryness
customthe crude was purified by column chromatography over silica gel
washeluting with Hexane

Sources & evidence

ORD record: ord-b7aa7d0fd18244f1bc4bc678824c5f11
Source dataset: uspto-grants-2016_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09233108B2

Reaction notes

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