Potassium Carbonate → Methyl 5-chloro-4-(1-methyl-1H-pyrazol-5-yl)thiophene-2-carboxylate

HRID 1961065Notes

Reaction equation

[CH3:1][N:2]1[C:6](B2OC(C)(C)C(C)(C)O2)=[CH:5][CH:4]=[N:3]1.C(=O)([O-])[O-].[K+].[K+].Br[C:23]1[CH:24]=[C:25]([C:29]([O:31][CH3:32])=[O:30])[S:26][C:27]=1[Cl:28]>O1CCOCC1.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:28][C:27]1[S:26][C:25]([C:29]([O:31][CH3:32])=[O:30])=[CH:24][C:23]=1[C:6]1[N:2]([CH3:1])[N:3]=[CH:4][CH:5]=1

Participants

Conditions

Temperature: 75 °C

Procedure

To a 300 mL sealed flask was added 1-methyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (8.14 g, 39.1 mmol), potassium carbonate (12.98 g, 94 mmol), methyl 4-bromo-5-chloro-2-thiophenecarboxylate (8 g, 31.3 mmol) and bis(tri-t-butylphosphine)palladium(0) (0.40 g, 0.78 mmol) in 1,4-dioxane (50 ml) and H2O (6 ml). After stirring for 90 min at 75° C., the reaction solution was diluted with DCM (100 mL) and washed with H2O. The organic layer was dried Na2SO4, filtered and concentrated. The reaction residue was purified on silica gel [hexanes/EtOAc, 2:1] to give the product [5.7 g, 70%] as a tan solid: LCMS (ES) m/z 258 (M+H)+.

Workup

customTo a 300 mL sealed flask
washwashed with H2O
filtrationfiltered
concentrationconcentrated
customThe reaction residue was purified on silica gel [hexanes/EtOAc, 2:1]
customto give the product [5.7 g, 70%] as a tan solid

Sources & evidence

ORD record: ord-ea7dc531e8984d0c81d99fcb390e327a
Source dataset: uspto-grants-2013_04
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08410158B2

Reaction notes

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