Sodium hydride → (E)-tert-butyl 4-(4-bromo-2,6-dimethylphenyl)but-2-enoate

HRID 735634Notes

Reaction equation

HRID 735634 reaction equation
COP([CH2:7][C:8]([O:10][C:11]([CH3:14])([CH3:13])[CH3:12])=[O:9])(OC)=O.[H-].[Na+].[Br:17][C:18]1[CH:23]=[C:22]([CH3:24])[C:21]([CH2:25][CH:26]=O)=[C:20]([CH3:28])[CH:19]=1.C([O-])(O)=O.[Na+]>C1COCC1>[Br:17][C:18]1[CH:23]=[C:22]([CH3:24])[C:21]([CH2:25]/[CH:26]=[CH:7]/[C:8]([O:10][C:11]([CH3:14])([CH3:13])[CH3:12])=[O:9])=[C:20]([CH3:28])[CH:19]=1

Participants

6

Reactant 4

HCID 24758Sodium hydrideHCID 516892Sodium BicarbonateHCID 4564495tert-Butyl DimethylphosphonoacetateHCID 578426542-(4-Bromo-2,6-dimethylphenyl)acetaldehyde

Product 1

HCID 57842697(E)-tert-butyl 4-(4-bromo-2,6-dimethylphenyl)but-2-enoateYield 63.4%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

tert-Butyl 2-(dimethoxyphosphoryl)acetate (2.5 mL, 12.7 mmol) was added dropwise to a suspension of NaH (490 mg, 12.7 mmol, 60% dispersion in oil) in THF (60 mL) at 0° C. After stirring for 30 min at ambient temperature a solution of 53A (2.6 g, 11.4 mmol) in THF (10 mL) and stirred for 1 h at ambient temperature. The reaction mixture was poured into 50 mL saturated NaHCO3/400 mL water and extracted with diethyl ether. The combined organics were dried over Na2SO4 and concentrated in vacuo. The crude solid was purified by flash chromatography (0% to 50% EtOAc in hexanes) to yield 53B (2.35 g, 63%) as a white solid. 1H NMR (400 MHz, CDCl3) δ ppm 1.44 (s, 9 H) 2.22 (s, 6 H) 3.43 (dd, J=5.56, 1.77 Hz, 2 H) 5.43 (dt, J=15.54, 2.02, 1.89 Hz, 1 H) 6.92 (dt, J=15.66, 5.56 Hz, 1 H) 7.17 (s, 2 H).

Workup

  1. extractionextracted with diethyl ether
  2. dry with materialThe combined organics were dried over Na2SO4
  3. concentrationconcentrated in vacuo
  4. customThe crude solid was purified by flash chromatography (0% to 50% EtOAc in hexanes)

Sources & evidence

ORD record
ord-9440863be692435f818e6ba329adb167
Source dataset
uspto-grants-2009_09
Patent number
US07592331B2

Reaction notes

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