Water → 1-(Propan-2-yl)-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole

HRID 2046921Notes

Reaction equation

HRID 2046921 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.C([O-])([O-])=O.[Cs+].[Cs+].[CH:21](I)([CH3:23])[CH3:22].O>CN(C=O)C.CCOC(C)=O>[CH:21]([N:12]1[CH:13]=[C:9]([B:4]2[O:5][C:6]([CH3:7])([CH3:8])[C:2]([CH3:14])([CH3:1])[O:3]2)[CH:10]=[N:11]1)([CH3:23])[CH3:22]

Participants

7

Reactant 4

HCID 962WaterHCID 6362Isopropyl iodideHCID 10796Cesium carbonateHCID 27740104-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole

Product 1

HCID 467380211-(Propan-2-yl)-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole

Reagents, catalysts & solvents 2

HCID 6228DimethylformamideSolventHCID 8857Ethyl AcetateSolvent

Conditions

Temperature
100 °C

Procedure

In a sealed tube, to a suspension of 4-(4,4,5,5-tetramethyl[1,3,2]dioxaborolan-2-yl)-1H-pyrazole (566.9 mg, 2.922 mmol) and Cs2CO3 (1.5442 g, 4.739 mmol) in DMF (6 mL), isopropyl iodide (753.3 mg, 4.431 mmol) was added and the reaction was allowed to stir at 100° C. for 19 h. Water was added to dilute the reaction and dissolve all salts that had formed, after which EtOAc was added and the two layers were separated. The organic layer was washed twice with water and once with brine, dried over anhydrous Na2SO4, filtered, and concentrated in vacuo. The combined aqueous layers were back extracted once with EtOAc, which was combined with the other organic batch. One obtained the title material as yellow oil. It was used without further purification in the next step. 1H NMR (400 MHz, CDCl3): δ=1.33 (s, 12H), 1.51 (d, J=6.8 Hz, 6H), 4.53 (spt, J=6.7 Hz, 1H), 7.75 (s, 1H), 7.80 (s, 1H). MS (AP+): m/z 235.98 (76) [MH+]. HPLC: tR=3.22 min (ZQ3, polar—5 min).

Workup

  1. additionwas added
  2. additionto dilute
  3. customthe reaction
  4. dissolutiondissolve all salts that
  5. customhad formed
  6. customthe two layers were separated
  7. washThe organic layer was washed twice with water and once with brine
  8. dry with materialdried over anhydrous Na2SO4
  9. filtrationfiltered
  10. concentrationconcentrated in vacuo
  11. extractionThe combined aqueous layers were back extracted once with EtOAc, which

Sources & evidence

ORD record
ord-41e27642d26140978b2b62d76ab4d684
Source dataset
uspto-grants-2013_11
Patent number
US08592448B2

Reaction notes

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