Cesium carbonate → 2-(2-Tert-butoxycarbonyl-ethyl)-5-[2-(5-methyl-2-phenyl-oxazol-4-yl)-ethoxy]-benzoic acid 2-trimethylsilanylethyl ester

HRID 1181106Notes

Reaction equation

HRID 1181106 reaction equation
[CH3:1][Si:2]([CH3:25])([CH3:24])[CH2:3][CH2:4][O:5][C:6](=[O:23])[C:7]1[CH:12]=[C:11]([OH:13])[CH:10]=[CH:9][C:8]=1[CH2:14][CH2:15][C:16]([O:18][C:19]([CH3:22])([CH3:21])[CH3:20])=[O:17].[CH3:26][C:27]1[O:31][C:30]([C:32]2[CH:37]=[CH:36][CH:35]=[CH:34][CH:33]=2)=[N:29][C:28]=1[CH2:38][CH2:39]OS(C1C=CC(C)=CC=1)(=O)=O.C([O-])([O-])=O.[Cs+].[Cs+]>CN(C=O)C>[CH3:25][Si:2]([CH3:24])([CH3:1])[CH2:3][CH2:4][O:5][C:6](=[O:23])[C:7]1[CH:12]=[C:11]([O:13][CH2:39][CH2:38][C:28]2[N:29]=[C:30]([C:32]3[CH:37]=[CH:36][CH:35]=[CH:34][CH:33]=3)[O:31][C:27]=2[CH3:26])[CH:10]=[CH:9][C:8]=1[CH2:14][CH2:15][C:16]([O:18][C:19]([CH3:22])([CH3:20])[CH3:21])=[O:17]

Participants

5

Reactant 3

HCID 10796Cesium carbonateHCID 120517392-(5-Methyl-2-phenyloxazol-4-yl)ethyl 4-methylbenzenesulfonateHCID 589791782-(2-Tert-butoxycarbonyl-ethyl)-5-hydroxy-benzoic acid 2-trimethylsilanyl-ethyl ester

Product 1

HCID 589792942-(2-Tert-butoxycarbonyl-ethyl)-5-[2-(5-methyl-2-phenyl-oxazol-4-yl)-ethoxy]-benzoic acid 2-trimethylsilanylethyl esterYield 78.1%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Conditions

Temperature
55 °C

Procedure

To a solution of 2-(2-tert-butoxycarbonyl-ethyl)-5-hydroxy-benzoic acid 2-trimethylsilanyl-ethyl ester (4.30 g, 11.7 mmol) and toluene-4-sulfonic acid 2-(5-methyl-2-phenyl-oxazol-4-yl)-ethyl ester (4.61 g, 12.9 mmol) in DMF (30 mL) was added Cs2CO3 (4.59 g, 14.1 mmol). The suspension was stirred at 55° C. for 12 h. The reaction mixture was quenched with H2O (200 mL) and extracted with EtOAc (3×100 mL). The combined organics were dried (Na2SO4) and concentrated to a residue, which was purified using silica gel chromatography (hexanes/EtOAc 9/1 to 8/2) to afford the title compound as a colorless oil (5.04 g, 78%). 1H NMR (400 MHz, CDCl3): δ 0.06 (s, 9H), 1.11 (t, 2H, J=8.8 Hz), 1.40 (s, 9H), 2.36 (s, 3H), 2.51 (t, 1H, J=7.8 Hz), 2.97 (t, 2H, J=6.8 Hz), 3.12 (t, 1H, J=7.8 Hz), 4.24 (t, 2H, J=6.8 Hz), 4.35 (t, 2H, J=8.8 Hz), 6.88 (dd, 1H, J=3.0, 8.3 Hz), 7.15 (d, 1H, J=8.3 Hz), 7.37-7.44 (m, 4H), 7.97 (d, 2H, J=7.8 Hz).

Workup

  1. customThe reaction mixture was quenched with H2O (200 mL)
  2. extractionextracted with EtOAc (3×100 mL)
  3. dry with materialThe combined organics were dried (Na2SO4)
  4. concentrationconcentrated to a residue, which
  5. customwas purified

Sources & evidence

ORD record
ord-9fa63d575cae4fc4bbff6a0c59bb7595
Source dataset
uspto-grants-2007_10
Patent number
US07282501B2

Reaction notes

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