Water → 2,4-Dimethoxy-5-pyrazin-2-yl-benzaldehyde

HRID 10665Notes

Reaction equation

HRID 10665 reaction equation
[O:1]1CCO[CH:2]1[C:6]1[C:7]([O:20][CH3:21])=[CH:8][C:9]([O:18][CH3:19])=[C:10]([C:12]2[CH:17]=[N:16][CH:15]=[CH:14][N:13]=2)[CH:11]=1.C1(C)C=CC(S(O)(=O)=O)=CC=1.O>CC(C)=O>[CH3:21][O:20][C:7]1[CH:8]=[C:9]([O:18][CH3:19])[C:10]([C:12]2[CH:17]=[N:16][CH:15]=[CH:14][N:13]=2)=[CH:11][C:6]=1[CH:2]=[O:1]

Participants

5

Reactant 3

HCID 962WaterHCID 6101p-Toluenesulfonic acidHCID 219809982-(5-[1,3]Dioxolan-2-yl-2,4-dimethoxy-phenyl)-pyrazine

Product 1

HCID 219810892,4-Dimethoxy-5-pyrazin-2-yl-benzaldehydeYield 34.7%

Reagents, catalysts & solvents 1

HCID 180AcetoneSolvent

Procedure

Ex-46D: 2-(5-[1,3]Dioxolan-2-yl-2,4-dimethoxy-phenyl)-pyrazine (1.02 g, 3.54 mmol) was dissolved in acetone and p-toluenesulfonic acid (100 mg, 0.53 mmol) and water (5 mL) were added. The solution was stirred for 3 h at room temperature, then concentrated on the rotavap. The resulting mixture was diluted with water (50 mL) and extracted with EtOAc (3×100 mL). The organic phase was washed with 25% saturated aqueous NaHCO3, dried over sodium sulfate, filtered, and concentrated. Drying gave 0.30 g of 2,4-dimethoxy-5-pyrazin-2-yl-benzaldehyde as a yellow solid (18% yield). 1H-NMR (CDCl3) δ 10.35 (s, 1H), 9.06 (d, J=2 Hz, 1H), 8.63–8.65 (m, 1H), 8.45 (d, J=2 Hz, 1H), 8.39 (s, 1H), 6.56 (s, 1H), 4.03 (s, 3H), 4.01 (s, 3H). HRMS m/z: calc. 244.0848, found 244.0853.

Workup

  1. concentrationconcentrated on the rotavap
  2. additionThe resulting mixture was diluted with water (50 mL)
  3. extractionextracted with EtOAc (3×100 mL)
  4. washThe organic phase was washed with 25% saturated aqueous NaHCO3
  5. dry with materialdried over sodium sulfate
  6. filtrationfiltered
  7. concentrationconcentrated
  8. customDrying

Sources & evidence

ORD record
ord-d427d4fef5b1445cbb0a32b5034db457
Source dataset
uspto-grants-2006_08
Patent number
US07094801B2

Reaction notes

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