2-Chloro-3-nitropyridine → HCID 67001482, compound

Participants

Reaction Conditions

Reaction Steps

Diisopropylethylamine (3.03 mL, 17.34 mmol) was added to a mixture of 2-chloro-3-nitropyridine (2.75 g, 17.34 mmol) and the product of Example 22B (4.48 g, 17.34 mmol) in dimethyl sulfoxide (20 mL). The mixture was heated at 95° C. under nitrogen for 7 hours and then cooled to room temperature. Ice water (200 mL) was added, and the mixture was extracted with ethyl acetate (2×100 mL). The organic phase was washed with saturated brine (60 mL), dried (MgSO4) and concentrated under vacuum to an oil (6.81 g). This material was dissolved in methanol (400 mL), and PtO2 (25 mg, 0.11 mmol) was added. The flask was evacuated and purged with nitrogen (3 cycles) and then with hydrogen (3 cycles). The suspension was stirred under hydrogen (1 atm) for 54 hours. The flask was evacuated and purged with nitrogen (3 cycles) and the black suspension was filtered through diatomaceous earth with a methanol (2×10 mL) rinse. Sodium methoxide (Aldrich, 25% in methanol, 12.01 g, 55.6 mmol) was added to the filtrate, and the mixture was heated at reflux for 41 hours. After cooling to room temperature, the reaction mixture was concentrated under vacuum. The residue was purified by chromatography (SiO2, eluted with methanol-CH2Cl2 (0:100-5:95), followed by crystallization from ethanol (10 mL) to provide the title compound: 1H NMR (300 MHz, CDCl3) δ ppm 1.48 (s, 9H), 2.27-2.40 (m, 1H), 2.78 (dd, J=13.5, 5.9 Hz, 1H), 2.91-3.20 (m, 3H), 3.55-3.68 (m, 1H), 3.69-3.80 (m, 1H), 3.99-4.19 (m, 2H), 6.95 (dd, J=7.7, 5.0 Hz, 1H), 7.23 (dd, J=7.7, 1.4 Hz, 1H), 7.61 (s, 1H), 8.18 (dd, J=5.0, 1.8 Hz, 1H); MS (ESI) m/z 319 (M+H)+.

Provenance & Evidence