4-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole → (S)-1-((2,2-dimethyl-1,3-dioxolan-4-yl)methyl)-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole

HRID 1947848Notes

Reaction equation

HRID 1947848 reaction equation
[CH3:1][C:2]1([CH3:14])[C:6]([CH3:8])([CH3:7])[O:5][B:4]([C:9]2[CH:10]=[N:11][NH:12][CH:13]=2)[O:3]1.C1(C)C=CC(S(O[CH2:25][C@H:26]2[CH2:30][O:29][C:28]([CH3:32])([CH3:31])[O:27]2)(=O)=O)=CC=1>CN(C=O)C>[CH3:31][C:28]1([CH3:32])[O:27][C@@H:26]([CH2:25][N:12]2[CH:13]=[C:9]([B:4]3[O:5][C:6]([CH3:7])([CH3:8])[C:2]([CH3:14])([CH3:1])[O:3]3)[CH:10]=[N:11]2)[CH2:30][O:29]1

Participants

4

Reactant 2

HCID 27740104-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazoleHCID 6993835(R)-(-)-2,2-Dimethyl-1,3-dioxolan-4-ylmethyl p-Toluenesulfonate

Product 1

HCID 67253006(S)-1-((2,2-dimethyl-1,3-dioxolan-4-yl)methyl)-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

A solution of 4-(4,4,5,5-Tetramethyl[1,3,2]dioxaborolan-2-yl)-1H-pyrazole (9.24 g, 47.6 mmol), (R)-(−)-(2,2-Dimethyl-1,3-dioxolan-4-yl)methyl p-toluenesulfonate (15.00 g, 52.38 mmol) and CsHCO3 (23.3 g, 71.4 mmol) in anhydrous DMF (236 mL) was heated to 100° C. for 16 h. The reaction mixture was cooled to rt and partitioned between EtOAc and H2O. The aqueous layer was re-extracted with EtOAc (3×) and the combined organic fractions were washed with H2O (2×) and brine (2×), dried over Na2SO4, filtered and concentrated in vacuo resulting in the title compound as an orange oil which was used in the next step without further purification.

Workup

  1. custompartitioned between EtOAc and H2O
  2. extractionThe aqueous layer was re-extracted with EtOAc (3×)
  3. washthe combined organic fractions were washed with H2O (2×) and brine (2×)
  4. dry with materialdried over Na2SO4
  5. filtrationfiltered
  6. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-ce092e2675164a2d8c4d985ff3cbd93a
Source dataset
uspto-grants-2013_03
Patent number
US08399433B2

Reaction notes

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