Cesium carbonate → (R)-4-[3-(tert-Butyldimethylsilanyloxy)-2-methylpropyl]-4H-benzo[1,4]oxazin-3-one

HRID 1191510Notes

Reaction equation

HRID 1191510 reaction equation
[O:1]1[C:6]2[CH:7]=[CH:8][CH:9]=[CH:10][C:5]=2[NH:4][C:3](=[O:11])[CH2:2]1.Br[CH2:13][C@@H:14]([CH3:24])[CH2:15][O:16][Si:17]([C:20]([CH3:23])([CH3:22])[CH3:21])([CH3:19])[CH3:18].C([O-])([O-])=O.[Cs+].[Cs+]>CC#N>[Si:17]([O:16][CH2:15][C@H:14]([CH3:24])[CH2:13][N:4]1[C:5]2[CH:10]=[CH:9][CH:8]=[CH:7][C:6]=2[O:1][CH2:2][C:3]1=[O:11])([C:20]([CH3:21])([CH3:22])[CH3:23])([CH3:18])[CH3:19]

Participants

5

Reactant 3

HCID 10796Cesium carbonateHCID 727572H-1,4-benzoxazin-3(4H)-oneHCID 11032834(S)-3-bromo-2-methylpropoxy-tert-butyldimethylsilane

Product 1

HCID 68910127(R)-4-[3-(tert-Butyldimethylsilanyloxy)-2-methylpropyl]-4H-benzo[1,4]oxazin-3-oneYield 85%

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent

Procedure

A reaction flask was charged with 4H-Benzo[1,4]oxazin-3-one (1.49 g, 10.0 mmol), (S)-(3-bromo-2-methylpropoxy)-tert-butyldimethylsilane (2.67 g, 10.0 mmol), and Cs2CO3 (4.89 g, 15.0 mmol) in MeCN (15 mL) and stirred at rt for 7 days. The reaction mixture was quenched with water and the product extracted into EtOAc. The combined organic layers were dried over Na2SO4, filtered, and concentrated. The product was purified by flash column chromatography (SiO2; n-heptane/EtOAc 2:1) to give the title compound (2.84 g, 85%).

Workup

  1. customThe reaction mixture was quenched with water
  2. extractionthe product extracted into EtOAc
  3. dry with materialThe combined organic layers were dried over Na2SO4
  4. filtrationfiltered
  5. concentrationconcentrated
  6. customThe product was purified by flash column chromatography (SiO2; n-heptane/EtOAc 2:1)

Sources & evidence

ORD record
ord-7043dfb3109c4c1fabf1937d43ee2596
Source dataset
uspto-grants-2014_03
Patent number
US08680115B2

Reaction notes

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