2-Methoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane → 1-[2-(oxan-2-yloxy)ethyl]-4-(tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole

HRID 445671Notes

Reaction equation

HRID 445671 reaction equation
I[C:2]1[CH:3]=[N:4][N:5]([CH2:7][CH2:8][O:9][CH:10]2[CH2:15][CH2:14][CH2:13][CH2:12][O:11]2)[CH:6]=1.C([Mg]Cl)(C)C.CO[B:23]1[O:27][C:26]([CH3:29])([CH3:28])[C:25]([CH3:31])([CH3:30])[O:24]1>C1COCC1>[O:11]1[CH2:12][CH2:13][CH2:14][CH2:15][CH:10]1[O:9][CH2:8][CH2:7][N:5]1[CH:6]=[C:2]([B:23]2[O:27][C:26]([CH3:29])([CH3:28])[C:25]([CH3:31])([CH3:30])[O:24]2)[CH:3]=[N:4]1

Participants

5

Reactant 3

HCID 109757592-Methoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolaneHCID 593418524-Iodo-1-(2-((tetrahydro-2H-pyran-2-yl)oxy)ethyl)-1H-pyrazoleHCID 178418918HCID 178418918, compound

Product 1

HCID 593418191-[2-(oxan-2-yloxy)ethyl]-4-(tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
0 °C

Procedure

To a solution of 4-iodo-1-[2-(tetrahydro-pyran-2-yloxy)-ethyl]-1H-pyrazole (Stage 106.1.3, 8.50 g, 26.4 mmol) in THF at 0° C. under argon was added dropwise iPrMgCl 2 M in THF (26.4 ml, 52.8 mmol). The RM was stirred at 0° C. for 1 h. Then 2-methoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (Aldrich, Buchs, Switzerland, 6.25 g, 52.8 mmol) was added at 0° C. and the solution was stirred again and allowed to warm to rt for 1 h. After that, the RM was quenched with saturated aqueous NH4Cl (140 ml) and extracted with EtOAc (3×). The combined organic layers were washed with saturated aqueous NH4Cl, dried over Na2SO4, filtered and evaporated. The residue was purified by flash chromatography (hexane/EtOAc 5% to 45%). The fractions containing product were combined and evaporated to dryness to give the title compound as a colorless oil. (HPLC: tR 3.23 min (Method A); M+H=323 MS-ES)

Workup

  1. stirringthe solution was stirred again
  2. temperatureto warm to rt for 1 h
  3. customAfter that, the RM was quenched with saturated aqueous NH4Cl (140 ml)
  4. extractionextracted with EtOAc (3×)
  5. washThe combined organic layers were washed with saturated aqueous NH4Cl
  6. dry with materialdried over Na2SO4
  7. filtrationfiltered
  8. customevaporated
  9. customThe residue was purified by flash chromatography (hexane/EtOAc 5% to 45%)
  10. additionThe fractions containing product
  11. customevaporated to dryness

Sources & evidence

ORD record
ord-715127d5b5404f7eaa39ed93c7f14167
Source dataset
uspto-grants-2013_07
Patent number
US08476294B2

Reaction notes

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