1-Bromo-3-methylbutane → HCID 68874755, compound

HRID 494632Notes

Reaction equation

HRID 494632 reaction equation
[CH3:1][O:2][C:3]1[CH:8]=[CH:7][C:6]([CH:9]([CH3:14])[C:10]([O:12][CH3:13])=[O:11])=[CH:5][CH:4]=1.CN(C)P(=O)(N(C)C)N(C)C.[CH:26]([N-]C(C)C)(C)C.[Li+].BrC[CH2:36][CH:37]([CH3:39])[CH3:38]>O1CCCC1>[CH3:1][O:2][C:3]1[CH:4]=[CH:5][C:6]([C:9]([CH3:26])([CH2:14][CH2:36][CH:37]([CH3:39])[CH3:38])[C:10]([O:12][CH3:13])=[O:11])=[CH:7][CH:8]=1

Participants

6

Reactant 4

HCID 78911-Bromo-3-methylbutaneHCID 12679HexamethylphosphoramideHCID 2724682Lithium diisopropylamideHCID 12398855Methyl 2-(4-methoxyphenyl)propanoate

Product 1

HCID 68874755HCID 68874755, compoundYield 92%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a solution of Example 155A (15 g. 77.2 mmol) and hexamethylphosphoric triamide (14.8 mL, 77.2 mmol) in 200 mL anhydrous tetrahydrofuran was added 2 M lithium diisopropyl amide (45 mL, 90 mmol) while maintaining the temperature below −70° C. After minutes at −78° C., 1-bromo-3-methylbutane (10.6 mL, 85 mmol) was added and the reaction stirred for 16 hours at room temperature. Most of the solvent was removed under vacuum and the residue partitioned between ethyl acetate and 1 N HCl. The crude product was purified on silica using 5% ethyl acetate in hexanes to give the product as a colorless oil (18.6 g, 92%). 1H NMR (300 MHz, CDCl3) δ ppm 0.86 (d, J=5.15 Hz, 3H) 0.88 (d, J=5.15 Hz, 3H) 1.04 (m, 2H) 1.51 (m, 1H) 1.51 (s, 3H) 1.88 (ddd, J=13.33, 10.57, 6.25 Hz, 1H) 2.02 (m, 1H) 3.64 (s, 3H) 3.79 (s, 3H) 6.85 (m, 2H) 7.23 (m, 2H).

Workup

  1. temperaturewhile maintaining the temperature below −70° C
  2. waitAfter minutes at −78° C.
  3. customMost of the solvent was removed under vacuum
  4. customthe residue partitioned between ethyl acetate and 1 N HCl
  5. customThe crude product was purified on silica using 5% ethyl acetate in hexanes

Sources & evidence

ORD record
ord-ad3dc50198ec44ff90ba635833cdc6a6
Source dataset
uspto-grants-2009_05
Patent number
US07538105B2

Reaction notes

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