Potassium Carbonate → Methyl 5-chloro-4-(1-ethyl-1H-pyrazol-5-yl)-2-thiophenecarboxylate

HRID 2392281Notes

Reaction equation

[CH2:1]([N:3]1[C:7](B2OC(C)(C)C(C)(C)O2)=[CH:6][CH:5]=[N:4]1)[CH3:2].C(=O)([O-])[O-].[K+].[K+].Br[C:24]1[CH:25]=[C:26]([C:30]([O:32][CH3:33])=[O:31])[S:27][C:28]=1[Cl:29]>COCCOC.O.C(Cl)Cl.CC(C)([P](C(C)(C)C)([Pd][P](C(C)(C)C)(C(C)(C)C)C(C)(C)C)C(C)(C)C)C>[Cl:29][C:28]1[S:27][C:26]([C:30]([O:32][CH3:33])=[O:31])=[CH:25][C:24]=1[C:7]1[N:3]([CH2:1][CH3:2])[N:4]=[CH:5][CH:6]=1

Participants

Conditions

Temperature: 70 °C

Procedure

To a 100 mL sealed flask was added 1-ethyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (2.61 g, 11.74 mmol), potassium carbonate (3.25 g, 23.48 mmol), methyl 4-bromo-5-chloro-2-thiophenecarboxylate (2 g, 7.83 mmol) and bis(tri-t-butylphosphine)palladium(0) (0.4 g, 0.78 mmol) in 1,2-dimethoxyethane (DME) (50 mL) and H2O (10 ml). After stirring for 3 h at 70° C., the reaction solution was diluted with DCM (100 mL) and washed with H2O. The organic layer was dried Na2SO4, filtered and concentrated. The residue was purified on silica gel [EtOAc/hexanes, 10-30%] to give the product [1.8 g, 85%] as an off white solid: LC-MS (ES) m/z 271 (M+H)+.

Workup

customTo a 100 mL sealed flask
washwashed with H2O
filtrationfiltered
concentrationconcentrated
customThe residue was purified on silica gel [EtOAc/hexanes, 10-30%]
customto give the product [1.8 g, 85%] as an off white solid

Sources & evidence

ORD record: ord-e60e32a7f8b74fdbb63f8acdbe11cb62
Source dataset: uspto-grants-2012_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08273782B2

Reaction notes

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