Ethylene Glycol → 2-Bromo-5-(1,3-dioxolan-2-YL)pyridine

HRID 2228400Notes

Reaction equation

HRID 2228400 reaction equation
[Br:1][C:2]1[CH:7]=[CH:6][C:5]([CH:8]=[O:9])=[CH:4][N:3]=1.[CH2:10](O)[CH2:11][OH:12]>C1C=CC=CC=1.C1(C)C=CC(S(O)(=O)=O)=CC=1>[Br:1][C:2]1[CH:7]=[CH:6][C:5]([CH:8]2[O:12][CH2:11][CH2:10][O:9]2)=[CH:4][N:3]=1

Participants

5

Reactant 2

HCID 174Ethylene GlycolHCID 117692346-Bromo-3-pyridinecarboxaldehyde

Product 1

HCID 184696682-Bromo-5-(1,3-dioxolan-2-YL)pyridineYield 70.8%

Reagents, catalysts & solvents 2

HCID 6101p-Toluenesulfonic acidCatalystHCID 241BenzeneSolvent

Procedure

A mixture of 2-bromo-5-pyridinecarboxaldehyde (2 Scheme 27, 12.0 g, 64.5 mmol) and ethylene glycol (5.4 mL, 96.8 mmol) and p-toluenesulfonic acid (100 mg) in benzene (150 mL) was refluxed in a Dean Stark apparatus for 16 h. The reaction mixture was cooled to room temperature, and the solution was extracted with cold water/ethyl acetate. The organic layer was dried (Na2SO4) and concentrated. The crude product was purified by column chromatography (1:4 ethyl acetate/hexanes) to afford a orange colored oil (10.5 g, 70%); 1H NMR (300 MHz, CDCl3) δ 3.82-3.96 (4 H), 5.64 (s, 1 H), 7.34 (d, J=8.10 Hz, 1 H), 7.49 (dd, J=8.10 Hz, 1 H), 8.29 (d, J=2.10 Hz, 1 H); 13C NMR (75 MHz, CDCl3) 65.5 (2C), 101.2, 128.0, 133.4, 137.0, 142.8, 148.8. HRMS (EI) calcd for C8H8BrNO2 228.9738, found 230.9718.

Workup

  1. temperaturewas refluxed in a Dean Stark apparatus for 16 h
  2. extractionthe solution was extracted with cold water/ethyl acetate
  3. dry with materialThe organic layer was dried (Na2SO4)
  4. concentrationconcentrated
  5. customThe crude product was purified by column chromatography (1:4 ethyl acetate/hexanes)

Sources & evidence

ORD record
ord-91d779376cb940dc8d8b7ec4b7dfde7d
Source dataset
uspto-grants-2002_07
Patent number
US06416861B1

Reaction notes

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