1,4-Dioxane → 5-Nitropyridine-2-carbaldehyde

Temperature

80 °C

To a stirred solution of compound 2-methyl-5-nitropyridine (30) (10 g, 72.5 mmol) in 1,4-dioxane (150 mL) was added SeO2 (9.5 g, 87.0 mmol) at room temperature. The resulting reaction mixture was stirred at 80° C. for 16 h. The reaction mixture was evaporated, the residue was diluted with water (100 mL), the resulting precipitate was separated by filtration and the filtrate was extracted with ethyl acetate (3×100 mL). The combined organic layer was washed with water (100 mL), brine (100 mL), the organic layer was dried over Na2SO4 and concentrated to give 31 (6.4 g, 58%) as a brown solid. Rf: 0.7 (30% EtOAc/pet-ether); 1H NMR (400 MHz, CDCl3): δ 10.18 (1H, s), 9.59 (1H, d, J=2.0 Hz), 8.68-8.65 (1H, m), 8.16 (1H, d, J=8.4 Hz)

1. customThe resulting reaction mixture
2. customThe reaction mixture was evaporated
3. additionthe residue was diluted with water (100 mL)
4. customthe resulting precipitate was separated by filtration
5. extractionthe filtrate was extracted with ethyl acetate (3×100 mL)
6. washThe combined organic layer was washed with water (100 mL), brine (100 mL)
7. dry with materialthe organic layer was dried over Na2SO4
8. concentrationconcentrated

ORD record

ord-7e534fcb9fae4cd794b52f9c55d79f1e

Source dataset

uspto-grants-2016_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09433622B2