Potassium Carbonate → 3-Pyridinecarboxylic acid, 5,6-dimethyl-, methyl ester

HRID 420729Notes

Reaction equation

HRID 420729 reaction equation
Br[C:2]1[CH:3]=[C:4](C(OC)=O)[CH:5]=[N:6][C:7]=1Cl.[C:13]([O-:16])([O-])=[O:14].[K+].[K+].[CH3:19]B1OB(C)OB(C)O1.O1[CH2:33][CH2:32]OCC1>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>[CH3:7][C:2]1[CH:3]=[C:4]([C:13]([O:16][CH3:19])=[O:14])[CH:5]=[N:6][C:32]=1[CH3:33]

Participants

6

Reactant 4

HCID 11430Potassium CarbonateHCID 312751,4-DioxaneHCID 574072TrimethylboroxineHCID 2764313Methyl 5-bromo-6-chloronicotinate

Product 1

HCID 580017543-Pyridinecarboxylic acid, 5,6-dimethyl-, methyl ester

Reagents, catalysts & solvents 1

HCID 178418397HCID 178418397, compoundCatalyst

Conditions

Temperature
110 °C

Procedure

To a mixture of methyl 5-bromo-6-chloro-3-pyridinecarboxylate (595 mg, 2.375 mmol), tetrakis(triphenylphosphine)palladium (0) (275 mg, 0.238 mmol) and K2CO3 (492 mg, 3.56 mmol) in dioxane (6.5 ml), trimethylboroxin (1.328 ml, 9.50 mmol) was added under argon. The reaction mixture was heated at 110° C. for 16 h. The reaction mixture was allowed to cool down, filtered through a pad of silica, and concentrated to give 857 mg of the crude material. Purification by flash chromatography using Flashmaster II, a 20 g silica gel cartridge, and mixtures of hexane and EtOAc as eluent afforded 276 mg of desired compound.

Workup

  1. additionwas added under argon
  2. temperatureto cool down
  3. filtrationfiltered through a pad of silica
  4. concentrationconcentrated
  5. customto give 857 mg of the crude material
  6. customPurification by flash chromatography

Sources & evidence

ORD record
ord-58b0d88912ff40c88f35dab3176fd16c
Source dataset
uspto-grants-2012_01
Patent number
US08097628B2

Reaction notes

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