Nitric Acid → 4-Nitro-2,3,5-trimethylpyridine, 1-oxide

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Reaction Conditions

Reaction Steps

A suspension of 2,3,5-collidine-N-oxide (3.77 g, 28 mmol) in conc. H2SO4 (8 mL) was cooled to 0° C. and fuming HNO3 (5 mL, 100 mmol) was added dropwise. The resulting transparent solution was stirred at 100° C. for 24 h, cooled to r.t., poured onto ice, and the pH was adjusted to 10. Work-up (CHCl3), drying (MgSO4), and evaporation gave the title compound, (97% yield, 97% purity). Rf (MeOH/EtOAc 1:9): 0.7. HPLC Rt: 4.756 min. 1H-NMR (CDCl3): δ 8.08 (s, 1H), 2.50 (s, 3H), 2.27 (s, 3H), 2.23 (s, 3H). m/z (%) 183.1 (M+1, 100%).

Provenance & Evidence