Cesium carbonate → 3-[4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazol-1-yl]-1lambda6-thietane-1,1-dione

HRID 1051570Notes

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+].Br[CH:22]1[CH2:25][S:24](=[O:27])(=[O:26])[CH2:23]1>CN(C)C=O>[CH3:1][C:2]1([CH3:14])[C:6]([CH3:7])([CH3:8])[O:5][B:4]([C:9]2[CH:13]=[N:12][N:11]([CH:22]3[CH2:25][S:24](=[O:27])(=[O:26])[CH2:23]3)[CH:10]=2)[O:3]1

Participants

Conditions

Temperature: 60 °C

Procedure

A 100-mL round bottomed flask was charged with 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (0.942 g, 4.85 mmol), N,N-dimethylformamide (20 mL) and cesium carbonate (3.16 g, 9.71 mmol). 3-Bromothietane 1,1-dioxide (0.925 g, 5.00 mmol) was added, and the reaction stirred at 60° C. overnight. The reaction mixture was cooled to room temperature and then partitioned between ethyl acetate and water. The aqueous phase was separated and extracted with ethyl acetate. The combined organic phases were washed with water and brine and concentrated to afford an oil. This material was purified via column chromatography on silica gel (eluting with 1:5 ethyl acetate-hexanes) to afford 3-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazol-1-yl)thietane 1,1-dioxide (0.172 g, 12% yield) as a white solid. MS (ESI, pos. ion) m/z 299 [M+H]+.

Workup

temperatureThe reaction mixture was cooled to room temperature
custompartitioned between ethyl acetate and water
customThe aqueous phase was separated
extractionextracted with ethyl acetate
washThe combined organic phases were washed with water and brine
concentrationconcentrated
customto afford an oil
customThis material was purified via column chromatography on silica gel (eluting with 1:5 ethyl acetate-hexanes)

Sources & evidence

ORD record: ord-1257f494abb34b9eb122e16073637705
Source dataset: uspto-grants-2016_07
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09388161B2

Reaction notes

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