Cesium carbonate → tert-Butyl 2-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazol-1-yl)acetate

HRID 1099045Notes

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.[CH3:15][C:16]([O:19][C:20](=[O:23])[CH2:21]Br)([CH3:18])[CH3:17].C(=O)([O-])[O-].[Cs+].[Cs+]>CN(C=O)C>[C:16]([O:19][C:20](=[O:23])[CH2:21][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)([CH3:18])([CH3:17])[CH3:15]

Participants

Conditions

Temperature: 90 °C

Procedure

To a solution of 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (1.5 g, 0.0077 mol) in DMF (25 mL) was added 2-bromoacetic acid 1,1-dimethylethyl ester (1.2 mL, 0.0085 mol) and cesium carbonate (3.8 g, 0.012 mol). The suspension was stirred at 90° C. overnight. The reaction mixture was cooled to RT and partitioned with ethyl acetate and water. The organic layer was washed with water, brine, and dried over MgSO4. The solution was concentrated to afford the desired compound (2.0 g, 84%). Analytical LC/MS: (M+H)+=309.4.

Workup

temperatureThe reaction mixture was cooled to RT
custompartitioned with ethyl acetate and water
washThe organic layer was washed with water, brine
dry with materialdried over MgSO4
concentrationThe solution was concentrated

Sources & evidence

ORD record: ord-1a052c96c7a3441ab79fe85cbb57726e
Source dataset: uspto-grants-2012_03
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08143251B2

Reaction notes

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