2-Isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane → 2-(3-Pyrrolidin-1-ylpropoxy)-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridine

HRID 1486945Notes

Reaction equation

HRID 1486945 reaction equation
C([Li])CCC.Br[C:7]1[CH:8]=[CH:9][C:10]([O:13][CH2:14][CH2:15][CH2:16][N:17]2[CH2:21][CH2:20][CH2:19][CH2:18]2)=[N:11][CH:12]=1.C(O[B:26]1[O:30][C:29]([CH3:32])([CH3:31])[C:28]([CH3:34])([CH3:33])[O:27]1)(C)C>C1COCC1>[N:17]1([CH2:16][CH2:15][CH2:14][O:13][C:10]2[CH:9]=[CH:8][C:7]([B:26]3[O:30][C:29]([CH3:32])([CH3:31])[C:28]([CH3:34])([CH3:33])[O:27]3)=[CH:12][N:11]=2)[CH2:21][CH2:20][CH2:19][CH2:18]1

Participants

5

Reactant 3

HCID 50177412-Isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolaneHCID 118523377HCID 118523377, compoundHCID 178418339Butyllithium

Product 1

HCID 595695912-(3-Pyrrolidin-1-ylpropoxy)-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridineYield 99%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

n-Butyllithium (5.68 mL, 14.20 mmol) was added dropwise to a mixture of 5-bromo-2-(3-pyrrolidin-1-ylpropoxy)pyridine (2.7 g, 9.47 mmol) and 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (2.64 g, 14.20 mmol) in THF (20 mL) at −78° C. over a period of 10 minutes under an inert atmosphere. The resulting mixture was allowed to warm to ambient temperature and stirred for 12 h. The reaction mixture was quenched by the addition of a sat. aqueous solution of ammonium chloride, extracted with EtOAc (2×50 mL) and the organic layer dried over Na2SO4, filtered and evaporated to afford the desired material (3.10 g, 99%) as a yellow oil. The product was used in the next step directly without further purification, NMR Spectrum: 1H NMR (400 MHz, CDCl3) δ 1.26-1.41 (12H, m), 1.77-1.80 (4H, m), 1.95-2.04 (2H, m), 2.50-2.58 (4H, m), 2.62 (2H, t), 4.37 (2H, t), 6.69 (1H, d), 7.91 (1H, d), 8.52 (1H, s). Mass Spectrum: m/z (ES+)[M+H]+=251.

Workup

  1. customThe reaction mixture was quenched by the addition of a sat. aqueous solution of ammonium chloride
  2. extractionextracted with EtOAc (2×50 mL)
  3. dry with materialthe organic layer dried over Na2SO4
  4. filtrationfiltered
  5. customevaporated

Sources & evidence

ORD record
ord-2a20810ebc8e46ff9fca92a6aeb2f1c4
Source dataset
uspto-grants-2016_08
Patent number
US09428503B2

Reaction notes

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