2-Isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane → 2-{5-[6-(3-Ethyl-oxetan-3-ylmethoxy)-hexyl]-thiophen-2-yl}-4,4,5,5-tetramethyl-[1,3,2]dioxaborolane

HRID 2242775Notes

Reaction equation

HRID 2242775 reaction equation
[CH2:1]([C:3]1([CH2:7][O:8][CH2:9][CH2:10][CH2:11][CH2:12][CH2:13][CH2:14][C:15]2[S:16][CH:17]=[CH:18][CH:19]=2)[CH2:6][O:5][CH2:4]1)[CH3:2].C([Li])CCC.C(O[B:29]1[O:33][C:32]([CH3:35])([CH3:34])[C:31]([CH3:37])([CH3:36])[O:30]1)(C)C>C1COCC1>[CH2:1]([C:3]1([CH2:7][O:8][CH2:9][CH2:10][CH2:11][CH2:12][CH2:13][CH2:14][C:15]2[S:16][C:17]([B:29]3[O:33][C:32]([CH3:35])([CH3:34])[C:31]([CH3:37])([CH3:36])[O:30]3)=[CH:18][CH:19]=2)[CH2:4][O:5][CH2:6]1)[CH3:2]

Participants

5

Reactant 3

HCID 50177412-Isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolaneHCID 592072913-Ethyl-3-(6-thiophen-2-yl-hexyloxymethyl)oxetaneHCID 178418339Butyllithium

Product 1

HCID 592073002-{5-[6-(3-Ethyl-oxetan-3-ylmethoxy)-hexyl]-thiophen-2-yl}-4,4,5,5-tetramethyl-[1,3,2]dioxaborolaneYield 72.3%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a stirred solution of 3-ethyl-3-(6-thiophen-2-yl-hexyloxymethyl)-oxetane (6.0 g, 21.28 mmol) in dry THF (70 ml) is added n-butyllithium (2.5 M in hexanes, 8.10 ml, 21.28 mmol) dropwise at −78° C. under nitrogen. After complete addition, the mixture is allowed to warm to room temperature, with stirring, over 2 h, followed by the addition of 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (3.96 g, 21.28 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 (3×70 ml). The combined organic extracts are washed with water, brine, and dried over sodium sulphate. 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 give a yellow oil (6.28 g, 72%). 1H NMR (300 MHz, CDCl3): δ (ppm) 7.45 (d, J=3.4 Hz, 1H, Ar—H), 6.85 (d, J=3.4 Hz, 1H, Ar—H), 4.44 (d, J=5.8 Hz, 2H, OCH2), 4.36 (d, J=5.8 Hz, 2H, OCH2), 3.51 (s, 2H, OCH2), 3.45 (t, J=6.4 Hz, 2H, OCH2), 2.83 (t, J=7.6 Hz 2H, ArCH2), 1.32-1.77 (m, 22H, CH2 and CH3), 0.88 (t, J=7.4 Hz, 3H, CH3); δ (ppm) 153.5 (quat.), 145.6 (quat.), 137.3 (CH), 125.9 (CH), 83.9 (quat.), 78.6 (OCH2), 73.4 (OCH2), 71.5 (OCH2), 43.4 (quat.), 31.6 (CH2), 30.1 (CH2), 29.4 (CH2), 28.8 (CH2), 26.8 (CH2), 25.9 (CH2), 24.8 (CH3), 8.2 (CH3); MS (m/e): 408 (M+, 0.5%), 223 (27), 165 (30), 141 (35), 123 (100), 97 (52).

Workup

  1. additionAfter complete addition
  2. customThe reaction is quenched with water
  3. extractionthe reaction mixture is extracted with ethyl acetate (3×70 ml)
  4. washThe combined organic extracts are washed with water, brine
  5. dry with materialdried over sodium sulphate
  6. customThe solvent is removed under reduced pressure
  7. customthe residue is purified by column chromatography on silica
  8. washeluting with petroleum ether/ethyl acetate (9:1)

Sources & evidence

ORD record
ord-d79e6c91643d4e7c84e7a880d5f40cca
Source dataset
uspto-grants-2010_03
Patent number
US07674397B2

Reaction notes

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