Reaction equation
[CH3:1][O:2][C:3]1[C:8]([N+:9]([O-:11])=[O:10])=[CH:7][CH:6]=[CH:5][C:4]=1B1OC(C)(C)C(C)(C)O1.Br[C:22]1[CH:23]=[C:24]([C:27]([OH:29])=[O:28])[S:25][CH:26]=1.C(=O)([O-])[O-].[Na+].[Na+].Cl>O1CCOCC1.O>[N+:9]([C:8]1[C:3]([O:2][CH3:1])=[C:4]([C:22]2[CH:23]=[C:24]([C:27]([OH:29])=[O:28])[S:25][CH:26]=2)[CH:5]=[CH:6][CH:7]=1)([O-:11])=[O:10]Participants
Reactant 4
Product 1
Reagents, catalysts & solvents 2
Procedure
2-(2-Methoxy-3-nitro-phenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane 4d (0.81 g, 2.9 mmol), 4-bromo-thiophene-2-carboxylic acid (0.3 g, 1.45 mmol), tetrakis (triphenylphosphine)palladium (80 mg, 0.073 mmol) and sodium carbonate (0.31 g, 2.9 mmol) were dissolved in a solvent mixture of 20 mL of 1,4-dioxane and 10 mL of water. The reaction was heated to reflux for 0.5 hours. The mixture was adjusted to pH 3 with 1 N hydrochloric acid and extracted with ethyl acetate (20 mL×3). The combined organic extracts were concentrated under reduced pressure and the residue was purified by silica gel column chromatography to obtain the title compound 4-(3-nitro-2-methoxy-phenyl)-thiophene-2-carboxylic acid 19a (0.54 g) as a brown oil, which was directly used in the next step.
Workup
- temperatureThe reaction was heated
- temperatureto reflux for 0.5 hours
- extractionextracted with ethyl acetate (20 mL×3)
- concentrationThe combined organic extracts were concentrated under reduced pressure
- customthe residue was purified by silica gel column chromatography
Sources & evidence
- ORD record
- ord-6b75d065aaba43979d898ef8c12a5b3e
- Source dataset
- uspto-grants-2014_02
- Patent number
- US08642637B2
Linked notes
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