Hydrochloric Acid → 4-(3-Nitro-2-methoxy-phenyl)-thiophene-2-carboxylic acid

HRID 384395Notes

Reaction equation

HRID 384395 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.C1C=CC([P]([Pd]([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)[P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1>[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

8

Reactant 4

HCID 313Hydrochloric AcidHCID 10340Sodium CarbonateHCID 6104094-Bromo-2-thiophenecarboxylic AcidHCID 574838002-(2-Methoxy-3-nitrophenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane

Product 1

HCID 574838444-(3-Nitro-2-methoxy-phenyl)-thiophene-2-carboxylic acidYield 133.4%

Reagents, catalysts & solvents 3

HCID 178418397HCID 178418397, compoundCatalystHCID 962WaterSolventHCID 312751,4-DioxaneSolvent

Procedure

2-(2-Methoxy-3-nitro-phenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane 6a (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 reaction was monitored by TLC until the disappearance of the starting materials. 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 51a (0.54 g) as a brown oil, which was directly used in the next step.

Workup

  1. temperatureThe reaction was heated
  2. temperatureto reflux for 0.5 hours
  3. extractionextracted with ethyl acetate (20 mL×3)
  4. concentrationThe combined organic extracts were concentrated under reduced pressure
  5. customthe residue was purified by silica gel column chromatography

Sources & evidence

ORD record
ord-4feccabb744b451fbe0c35050de517f7
Source dataset
uspto-grants-2013_02
Patent number
US08367710B2

Reaction notes

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