Cesium carbonate → ethyl 3-(4-bromo-1H-pyrazol-1-yl)-3-methylbutanoate

HRID 2279851Notes

Reaction equation

HRID 2279851 reaction equation
[Br:1][C:2]1[CH:3]=[N:4][NH:5][CH:6]=1.[CH2:7]([O:9][C:10](=[O:15])[CH:11]=[C:12]([CH3:14])[CH3:13])[CH3:8].C(=O)([O-])[O-].[Cs+].[Cs+]>CN(C=O)C.O>[Br:1][C:2]1[CH:3]=[N:4][N:5]([C:12]([CH3:14])([CH3:13])[CH2:11][C:10]([O:9][CH2:7][CH3:8])=[O:15])[CH:6]=1

Participants

6

Reactant 3

HCID 10796Cesium carbonateHCID 12516Ethyl 3,3-dimethylacrylateHCID 163754-Bromopyrazole

Product 1

HCID 67813664ethyl 3-(4-bromo-1H-pyrazol-1-yl)-3-methylbutanoate

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6228DimethylformamideSolvent

Procedure

A solution of 4-bromo-1H-pyrazole (3.42 g, 23.43) and 3-methyl-2-butenoic acid ethyl ester (1 g, 7.81 mmol) in DMF (50 mL) was treated with cesium carbonate (10.1 g, 31.07) and allowed to stir for 3 hours at room temperature. The reaction mixture was diluted with water (30 mL) and extracted with EtOAc (3×30 mL). The combined extracts were dried over sodium sulfate and concentrated to afford the desired product, 1.1 g (51%) yield. 1H NMR (300 MHz, CDCl3) δ 7.51 (s, 1H), 7.45 (s, 1H), 3.98-4.05 (m, 2H), 2.82 (s, 2H), 1.62 (s, 6H), 1.18-1.10 (t, 3H).

Workup

  1. extractionextracted with EtOAc (3×30 mL)
  2. dry with materialThe combined extracts were dried over sodium sulfate
  3. concentrationconcentrated

Sources & evidence

ORD record
ord-8d39407c162d4769a4e16525835c89db
Source dataset
uspto-grants-2015_09
Patent number
US09133224B2

Reaction notes

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