Sodium hydride → 2-Methoxy-3,6-dimethyl-5-nitropyridine

Temperature

70 °C

Dimethyl sulfoxide (35 mL) was added to a dry round-bottomed flask containing NaH (1.82 g, 45.5 mmol, 60% in mineral oil). The resulting suspension was heated at 70° C. for 35 min during which time the suspension became a solution. The reaction mixture was cooled to room temperature, trimethylsulfoxonium iodide (10.0 g, 45.5 mmol) was added, and the mixture was stirred at room temperature for 30 min. 2-Methoxy-3-methyl-5-nitropyridine (4.50 g, 26.80 mmol) was added and the resulting dark red solution was stirred at room temperature for 30 min, at which time TLC showed complete consumption of starting material. The reaction mixture was transferred to a separatory funnel containing water (30 mL), and the aqueous layer was extracted with EtOAc (3×100 mL). The combined organic layers were washed with brine, dried over MgSO4, filtered and concentrated. The residue was purified by MPLC (silica gel, 20% ethyl acetate in hexanes) to afford 2-methoxy-3,6-dimethyl-5-nitropyridine (2.00 g, 41% yield) as a colorless solid identical to that prepared by the previous method: mp 85.5-86.2° C.; 1H NMR (400 MHz, CDCl3) δ 8.08 (s, 1H), 4.02 (s, 3H), 2.77 (s, 3H), 2.20 (s, 3H).

1. temperatureThe reaction mixture was cooled to room temperature
2. stirringthe resulting dark red solution was stirred at room temperature for 30 min, at which time TLC
3. customconsumption of starting material
4. customThe reaction mixture was transferred to a separatory funnel
5. additioncontaining water (30 mL)
6. extractionthe aqueous layer was extracted with EtOAc (3×100 mL)
7. washThe combined organic layers were washed with brine
8. dry with materialdried over MgSO4
9. filtrationfiltered
10. concentrationconcentrated
11. customThe residue was purified by MPLC (silica gel, 20% ethyl acetate in hexanes)

ORD record

ord-2ffc4045885a4dbc8b2fe7f78e4dd938

Source dataset

uspto-grants-2013_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08372847B2