Methyl iodide → Ethyl 2-allyl-2-(tert-butoxycarbonyl(methyl)amino)-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)hexanoate

HRID 1778568Notes

Reaction equation

HRID 1778568 reaction equation
[CH2:1]([C:4]([NH:23][C:24]([O:26][C:27]([CH3:30])([CH3:29])[CH3:28])=[O:25])([CH2:10][CH2:11][CH2:12][CH2:13][B:14]1[O:18][C:17]([CH3:20])([CH3:19])[C:16]([CH3:22])([CH3:21])[O:15]1)[C:5]([O:7][CH2:8][CH3:9])=[O:6])[CH:2]=[CH2:3].[CH3:31][Si]([N-][Si](C)(C)C)(C)C.[Na+].CI>C1COCC1>[CH2:1]([C:4]([N:23]([C:24]([O:26][C:27]([CH3:29])([CH3:28])[CH3:30])=[O:25])[CH3:31])([CH2:10][CH2:11][CH2:12][CH2:13][B:14]1[O:18][C:17]([CH3:20])([CH3:19])[C:16]([CH3:21])([CH3:22])[O:15]1)[C:5]([O:7][CH2:8][CH3:9])=[O:6])[CH:2]=[CH2:3]

Participants

5

Reactant 3

HCID 6328Methyl iodideHCID 2724254Sodium bis(trimethylsilyl)amideHCID 66833330Ethyl-2-allyl-2-(tert-butoxycarbonylamino)-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)hexanoate

Product 1

HCID 89514314Ethyl 2-allyl-2-(tert-butoxycarbonyl(methyl)amino)-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)hexanoateYield 79%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
0 °C

Procedure

Ethyl 2-allyl-2-(tert-butoxycarbonylamino)-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)hexanoate (0.64 g, 1.50 mmol) was dissolved in THF (5 mL) and cooled to 0° C. NaHMDS (1 M solution in THF, 2.5 mL, 2.5 mmol) was added dropwise and the reaction was stirred for 20 min. Methyl iodide (0.47 mL, 7.5 mmol) was added and the reaction was warmed to room temperature and stirred overnight. The reaction was quenched with saturated NH4Cl solution (5 mL), diluted with ethyl acetate, washed successively with saturated sodium bicarbonate solution and saturated aqueous sodium chloride, dried over MgSO4, and concentrated in vacuo. The residue was chromatographed on silica gel eluting with 2-25% ethyl acetate in heptane to afford the desired product (0.518 g, 79%). Rf 0.53 (30% ethyl acetate in heptane). 1H NMR (CDCl3, 300 MHz) δ 5.78-5.62 (m, 1H), 5.15-5.03 (m, 2H), 4.12 (q, J=9.0 Hz, 2H), 2.90 (s, 3H), 2.89-2.81 (m, 1H), 2.58-2.51 (m, 1H), 1.94-1.83 (m, 1H), 1.76-1.66 (m, 1H), 1.54-1.08 (m, 29H), 0.77 (t, J=8.0 Hz, 2H). ESI MS found for C23H42B1N1O6 m/z [440.2 (M+1)].

Workup

  1. temperaturethe reaction was warmed to room temperature
  2. stirringstirred overnight
  3. customThe reaction was quenched with saturated NH4Cl solution (5 mL)
  4. additiondiluted with ethyl acetate
  5. washwashed successively with saturated sodium bicarbonate solution and saturated aqueous sodium chloride
  6. dry with materialdried over MgSO4
  7. concentrationconcentrated in vacuo
  8. customThe residue was chromatographed on silica gel eluting with 2-25% ethyl acetate in heptane

Sources & evidence

ORD record
ord-730d537120d74e9b981a22447e031ec0
Source dataset
uspto-grants-2016_02
Patent number
US09266908B2

Reaction notes

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