2-Isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane → 2-{4-[6-((3-Ethyloxetan-3-yl)methoxy)hexyl]phenyl}-4,4,5,5-tetramethyl-[1,3,2]-dioxaborolane

HRID 2242781Notes

Reaction equation

HRID 2242781 reaction equation
Br[C:2]1[CH:7]=[CH:6][C:5]([CH2:8][CH2:9][CH2:10][CH2:11][CH2:12][CH2:13][O:14][CH2:15][C:16]2([CH2:20][CH3:21])[CH2:19][O:18][CH2:17]2)=[CH:4][CH:3]=1.C([Li])CCC.C(O[B:31]1[O:35][C:34]([CH3:37])([CH3:36])[C:33]([CH3:39])([CH3:38])[O:32]1)(C)C>C1COCC1>[CH2:20]([C:16]1([CH2:15][O:14][CH2:13][CH2:12][CH2:11][CH2:10][CH2:9][CH2:8][C:5]2[CH:6]=[CH:7][C:2]([B:31]3[O:35][C:34]([CH3:37])([CH3:36])[C:33]([CH3:39])([CH3:38])[O:32]3)=[CH:3][CH:4]=2)[CH2:19][O:18][CH2:17]1)[CH3:21]

Participants

5

Reactant 3

HCID 50177412-Isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolaneHCID 592073013-((6-(4-Bromophenyl)hexyloxy)methyl)-3-ethyloxetaneHCID 178418339Butyllithium

Product 1

HCID 592072862-{4-[6-((3-Ethyloxetan-3-yl)methoxy)hexyl]phenyl}-4,4,5,5-tetramethyl-[1,3,2]-dioxaborolaneYield 71%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a stirred solution of 3-[6-(4-bromophenyl)hexyloxymethyl]-3-ethyl-oxetane (2.0 g, 5.63 mmol) in dry THF (20 ml) is added n-butyllithium (2.5 M in hexanes, 2.25 ml, 5.63 mmol) dropwise at −78° C. under nitrogen, with stirring. After complete addition, the mixture is stirred for another 20 min, followed by the addition of 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (1.05 g, 5.64 mmol). The resultant mixture is stirred overnight at room temperature. The reaction is quenched with water, and the reaction mixture is extracted with ethyl acetate (3×50 ml). The combined organic extracts are washed with water, brine, and dried (Na2SO4). The solvent is removed under reduced pressure and the residue is purified by column chromatography on silica, eluting with petroleum ether/ethyl acetate (9:1 to 7:3), to give a brown oil (1.60 g, 71%). 1H NMR (300 MHz, CDCl3): δ(ppm) 7.72 (d, J=8.1 Hz, 2H, Ar—H), 7.17 (d, J=8.1 Hz, 2H, Ar—H), 4.43 (d, J=5.8 Hz, 2H, OCH2), 4.35 (d, J=5.8 Hz, 2H, OCH2), 3.48 (s, 2H, OCH2), 3.41 (t, J=6.4 Hz, 2H, OCH2), 2.60 (t, J=7.9 Hz, 2H, ArCH2), 1.72 (q, J=7.5 Hz, 2H, CH2), 1.56 (m, 4H, CH2), 1.32 (m, 14H, CH2 and CH3); 0.86 (t, J=7.5 Hz 3H, CH3); 13C NMR (75 MHz, CDCl3): δ (ppm) 146.1 (quat.), 134.8 (CH), 127.8 (CH), 83.5 (quat.), 78.5 (OCH2), 73.3 (OCH2), 71.5 (OCH2), 43.4 (quat.), 36.1 (CH2), 31.3 (CH2), 29.5 (CH2), 29.0 (CH2), 26.7 (CH2), 26.0 (CH2), 24.8 (CH3), 8.2 (CH3).

Workup

  1. additionAfter complete addition
  2. stirringthe mixture is stirred for another 20 min
  3. customThe reaction is quenched with water
  4. extractionthe reaction mixture is extracted with ethyl acetate (3×50 ml)
  5. washThe combined organic extracts are washed with water, brine
  6. dry with materialdried (Na2SO4)
  7. customThe solvent is removed under reduced pressure
  8. customthe residue is purified by column chromatography on silica
  9. washeluting with petroleum ether/ethyl acetate (9:1 to 7:3)

Sources & evidence

ORD record
ord-ed5788b8deba45afb161fa31932009bb
Source dataset
uspto-grants-2010_03
Patent number
US07674397B2

Reaction notes

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