Diisobutylaluminum hydride → 4,6-Dichloropicolinaldehyde

To a solution of 2-carbomethoxy-4,6-dichloropyridine (206 mg, 1 mmol) in 4 mL of dry toluene at -78° in a 25 mL round bottomed flask fitted with a stirrer bar and rubber septum, prepared by the procedure of D. G. Markees (vide supra) was slowly added 1.33 mL of 1.5M DIBAL (2 equivalents) in toluene. The mixture was stirred at -78° for 45 minutes, then at -50° for 30 minutes. The mixture was quenched with saturated ammonium chloride. After the effervescence ceased, the mixture was poured into 10 mL of water and extracted with 2×20 mL of methylene chloride. The organic layer was dried over anhydrous MgSO4, filtered and the solvent volume reduced. The residue was purifed by flash chromatography (85/15 hexane/ethyl acetate). Recovered 75 mg of product. NMR (CDCl3 200 Mhz): δ 7.59 (d, 1H, J=2 Hz), 7.87 (d, 1H, J=2 Hz), 9.97 (s, 1H).

1. customrubber septum, prepared by the procedure of D
2. waitat -50° for 30 minutes
3. customThe mixture was quenched with saturated ammonium chloride
4. additionthe mixture was poured into 10 mL of water
5. extractionextracted with 2×20 mL of methylene chloride
6. dry with materialThe organic layer was dried over anhydrous MgSO4
7. filtrationfiltered
8. customRecovered 75 mg of product

ORD record

ord-e5d2a5a6cca54cb9a4d46688f43bd6ba

Source dataset

uspto-grants-1998_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05750549