Reaction #70146

Reaction equation

2-Chloro-3-pyridinecarboxaldehyde

4-fluorobenzenesulfinic acid sodium salt

→

desired product

2-(4-Fluorobenzenesulfonyl)-pyridine-3-carboxaldehyde

Solvents

water

DMSO

Conditions

Workup

1. 1
   TemperatureUpon cooling to ambient the mixture
2. 2
   Extractionextracted with EtOAc (3×)
3. 3
   WashThe combined organics were washed with water, brine
4. 4
   Dryingdried (MgSO4)
5. 5
   Otherevaporated to dryness
6. 6
   Otherto afford 7.89 g of crude product
7. 7
   OtherThe crude compound was pre-absorbed onto silica
8. 8
   Otherpurified
9. 9
   Otherby dry pad suction column chromatography
10. 10
    Washeluting with heptane using an EtOAc gradient

Procedure

2-Chloro-3-pyridinecarboxaldehyde (4.04 g, 2.86 mmol) and 4-fluorobenzenesulfinic acid sodium salt (5.73 g, 3.14 mmol) were dissolved in DMSO (100 ml) and the mixture was heated at 100° C. for 72 h under nitrogen. Upon cooling to ambient the mixture was diluted with water (500 ml) and extracted with EtOAc (3×). The combined organics were washed with water, brine, dried (MgSO4) and evaporated to dryness to afford 7.89 g of crude product. The crude compound was pre-absorbed onto silica and purified by dry pad suction column chromatography, eluting with heptane using an EtOAc gradient, to afford 4.14 g (41%) of the desired product as a yellow solid (plates) (MP=131-131.3° C.; IR=1691 cm−1; HPLC=7.21 min>99%).

Source