Iodine → 2-Pyridinecarboxylic acid, 3-(4-methylbenzoyl)-

HRID 1857797Notes

Reaction equation

HRID 1857797 reaction equation
II.[Mg].Br[C:5]1[CH:10]=[CH:9][C:8]([CH3:11])=[CH:7][CH:6]=1.[N:12]1[CH:17]=[CH:16][CH:15]=[C:14]2[C:18]([O:20][C:21](=[O:22])[C:13]=12)=[O:19]>C1COCC1>[CH3:11][C:8]1[CH:9]=[CH:10][C:5]([C:18]([C:14]2[C:13]([C:21]([OH:20])=[O:22])=[N:12][CH:17]=[CH:16][CH:15]=2)=[O:19])=[CH:6][CH:7]=1

Participants

6

Reactant 4

HCID 807IodineHCID 78054-BromotolueneHCID 69688Furo[3,4-b]pyridine-5,7-dioneHCID 5462224Magnesium

Product 1

HCID 103319012-Pyridinecarboxylic acid, 3-(4-methylbenzoyl)-

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent3×

Procedure

Iodine (catalytic amount) was added to a THF (30 ml) suspension of magnesium (2.4 g) in a nitrogen atmosphere at room temperature with stirring, and then a THF (20 ml) solution of 4-bromotoluene (17.1 g) was dropwise added thereto and stirred for 1 hour. The resulting mixture was added to a THF (50 ml) solution of 2,3-pyridinedicarboxylic acid anhydride (12.7 g) at 0-5° C. with stirring, and this was stirred for additional 30 minutes as it was and then for 1 hour at room temperature. The solvent was removed from the reaction mixture by distillation, and water (30 ml) was added to the residue, which was then adjusted the pH to 1.0 with hydrochloric acid. The mixture was extracted with dichloromethane, washed with water and dried. Then, the solvent was removed by distillation. Dichloromethane (about 10 ml) was added to the residue, and then isopropyl ether (about 70 ml) was added thereto. This was stirred for 16 hours at room temperature, and 3-(4-methylbenzoyl)-2-pyridinecarboxylic acid was obtained as colorless crystals (5.0 g). m.p. 168-170° C. (recrystallized from dichloromethane-ethyl acetate) NMR(200 MHz, CDCl3) ppm: 2.41(3H,s), 7.24(2H,d,J=8.4 Hz), 7.62(2H,d,J=8.4 Hz), 7.70(1H,dd,J=8.0,4.8 Hz), 7.85(1H,dd,J=8.0,1.5 Hz), 8.77(1H,dd,J=4.8,1.5 Hz).

Workup

  1. stirringstirred for 1 hour
  2. stirringwith stirring
  3. stirringthis was stirred for additional 30 minutes as it
  4. customThe solvent was removed from the reaction mixture by distillation, and water (30 ml)
  5. additionwas added to the residue, which
  6. extractionThe mixture was extracted with dichloromethane
  7. washwashed with water
  8. customdried
  9. customThen, the solvent was removed by distillation
  10. additionDichloromethane (about 10 ml) was added to the residue
  11. additionisopropyl ether (about 70 ml) was added
  12. stirringThis was stirred for 16 hours at room temperature

Sources & evidence

ORD record
ord-1baa4a477c74441d99326eee08333f5b
Source dataset
uspto-grants-2000_11
Patent number
US06147071

Reaction notes

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