Cesium carbonate → HCID 68704975, compound

HRID 655255Notes

Reaction equation

HRID 655255 reaction equation
[NH:1]1[CH:5]=[C:4]([B:6]2[O:14][C:11]([CH3:13])([CH3:12])[C:8]([CH3:10])(C)[O:7]2)[CH:3]=[N:2]1.C([O-])([O-])=O.[Cs+].[Cs+].Br[CH2:22][C:23](=[O:26])[CH2:24][CH3:25]>CN(C)C=O>[CH3:13][C:11]1([CH3:12])[CH:8]([CH3:10])[O:7][B:6]([C:4]2[CH:5]=[N:1][N:2]([CH2:22][C:23](=[O:26])[CH2:24][CH3:25])[CH:3]=2)[O:14]1

Participants

5

Reactant 3

HCID 10796Cesium carbonateHCID 131561-Bromo-2-butanoneHCID 27740104-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole

Product 1

HCID 68704975HCID 68704975, compoundYield 14.8%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Conditions

Temperature
90 °C

Procedure

Pyrazole-4-boronic acid pinacol ester (1 g, 1 equiv, 5.15 mmol) was dissolved in dimethylformamide (15 mL) followed by the addition of Cs2CO3 (0.86 g, 1.5 equiv, 7.73 mmol) and 1-bromo-2-butanone (1.1 equiv, 5.67 mmol, 0.86 g). The mixture was heated at 90° C. overnight. The reaction was extracted into ethyl acetate and washed with water (3×) and brine (3×). The filtrate was concentrated in vacuo onto silica gel and purified by flash chromatography (SiO2, CH2Cl2:CH3OH 100:0-80:20) to return the title compound (0.19 g, 14% yield). 1H NMR 500 MHz (DMSO) δ 0.97 (3H, t) 1.26 (12H, s), 2.50 (2H, q), 4.71 (2H, s), 7.65 (1H, s), 8.04 (1H, s). MS m/z 265 (M+H+)+.

Workup

  1. extractionThe reaction was extracted into ethyl acetate
  2. washwashed with water (3×) and brine (3×)
  3. concentrationThe filtrate was concentrated in vacuo onto silica gel
  4. custompurified by flash chromatography (SiO2, CH2Cl2:CH3OH 100:0-80:20)

Sources & evidence

ORD record
ord-3bf984ee05744ff89db3bb5d48e54147
Source dataset
uspto-grants-2011_12
Patent number
US08071581B2

Reaction notes

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