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

HRID 595207Notes

Reaction equation

C(=O)([O-])[O-].[Cs+].[Cs+].[Br:7][C:8]1[CH:9]=[N:10][NH:11][CH:12]=1.CS(O[CH:18]1[CH2:23][CH2:22][CH:21]([C:24]([O:26][CH2:27][CH3:28])=[O:25])[CH2:20][CH2:19]1)(=O)=O>CN(C=O)C.O>[Br:7][C:8]1[CH:9]=[N:10][N:11]([CH:18]2[CH2:23][CH2:22][CH:21]([C:24]([O:26][CH2:27][CH3:28])=[O:25])[CH2:20][CH2:19]2)[CH:12]=1

Participants

Conditions

Temperature: 80 °C

Procedure

Cesium carbonate (1.96 g, 6 mmol) and 4-bromopyrazole (321 mg, 2.2 mmol) were added to a solution of ethyl 4-[(methylsulfonyl)oxy]cyclohexanecarboxylate (0.50 g, 2 mmol) in DMF (10 mL). The mixture was stirred at 80° C. for 16 hours. Upon cooling to room temperature, the mixture was diluted with water and extracted with ethyl acetate. The organic layer was dried over sodium sulfate, filtered, and concentrated under reduced pressure. The residue was purified by chromatography on silica gel (ethyl acetate/petroleum ether) to give ethyl 4-(4-bromo-1H-pyrazol-1-yl)cyclohexanecarboxylate. MS ESI calc'd. for C12H18BrN2O2 [M+H]+ 301 and 303. found 301 and 303. 1H NMR (400 MHz, CDCl3): δ 7.45 (s, 1H), 7.44 (s, 1H), 4.23 (q, J=7.2 Hz, 2H), 2.46-2.38 (m, 1H), 2.26-2.18 (m, 4H), 2.06-1.98 (m, 2H), 1.86-1.78 (m, 3H), 1.36 (t, J=7.2 Hz, 3H).

Workup

temperatureUpon cooling to room temperature
extractionextracted with ethyl acetate
dry with materialThe organic layer was dried over sodium sulfate
filtrationfiltered
concentrationconcentrated under reduced pressure
customThe residue was purified by chromatography on silica gel (ethyl acetate/petroleum ether)

Sources & evidence

ORD record: ord-a976b07ec88948c283c936e26a7d3e1e
Source dataset: uspto-grants-2016_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09242984B2

Reaction notes

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