Nitric Acid → Thiomorpholine, 4-(2,6-difluoro-4-nitrophenyl)-, 1,1-dioxide

Participants

Reaction Steps

To a suspension of 4-(2,6-difluorophenyl)thiomorpholine 1,1-dioxide (Step 1, 300 g, 1.21 mol) in 3 L of acetic acid, nitric acid (255 mL, ca. 6 mol, fuming, 90%) is added over 30 minutes at ambient temperature. A yellow precipitate forms within minutes and increases over time. The reaction is kept at room temperature for 18 h and is then poured into 6 L of water. After stirring for 2 h, the yellow suspension is filtered. The precipitate is washed with water (1.5 L×3) and ethanol (0.5 L×2) and dried at 50° C. overnight to give the title compound, 1H NMR (DMSO-d6) δ 8.05 (m, 2H), 3.69 (m, 4H), 3.26 (m, 4H).

Provenance & Evidence