1,2-(Methylenedioxy)-4-nitrobenzene

In air, benzo[d][1,3]dioxane 1a (0.5 mmol, 61 mg), I₂O₅ (2.5 mmol, 835 mg), Na_{NO2 (2.5 mmol, 173 mg), 2 mL CH3NO2 and 0.1 mL water were added sequentially to a 10 mL sealed pressure-resistant tube. The reaction was carried out at 15 °C with vigorous magnetic stirring for 2 h. The reaction was monitored by TLC.}

After the reaction was complete, anhydrous Na₂SO₃ was added to quench the reaction. First, 15 mL of saturated Na₂SO₃ was added to the reaction solution. The aqueous phase was washed with 15 mL of CH₂Cl₂, the organic phases were combined, dried over anhydrous Na₂SO₄, filtered, and the solvent in the filtrate was removed under reduced pressure. Column chromatography (ethyl acetate: petroleum ether = 1:5) was used to separate 70 mg of a pale yellow solid, 1,2-methylenedioxy-4-nitrobenzene, in 84% yield.

yellow fine crystalline powder

1,2-(Methylenedioxy)-4-nitrobenzene undergoes continuous hydrogenation in supercritical CO₂ with poly siloxane-supported noble metal catalyst in small flow reactor.

Journal of Heterocyclic Chemistry, 28, p. 625, 1991 DOI: 10.1002/jhet.5570280316
Tetrahedron, 64, p. 4999, 2008 DOI: 10.1016/j.tet.2008.03.085

1,2-(Methylenedioxy)-4-nitrobenzene undergoes continuous hydrogenation in supercritical CO₂ with poly siloxane-supported noble metal catalyst in small flow reactor.