Abstract
Reduction of 4-nitro-2, 6-lutidine 1-oxide (Ia) and 4-nitro-3-picoline 1-oxide (Ib) under various conditions was examined. Upon catalytic reduction with palladium-charcoal in aqueous solution, (Ia) and (Ib) were respectively reduced to 4-amino-2, 6-lutidine 1-oxide (IIa) and 4-amino-3-picoline 1-oxide (IIb). However, in methanolic solution or 10% hydrochloric acid solution, the reduction did not proceed smoothly and azo derivatives (Va, Vb) were obtained as a by-product. In glacial acetic acid, to which a small amount of acetic anhydride had been added, the reduction proceeded smoothly and 4-amino derivatives (IIIa, IIIb) were obtained. By the reduction of (Ia) and (Ib) with hydrogen sulfide or sodium nitrite, 4, 4'-azo-2, 6-lutidine 1, 1'-dioxide (Va) and 4, 4'-azo-3-picoline 1, 11'-dioxide (Vb) were obtained. When zinc dust was used as a reducing agent 4, 4'-azoxy 1, 1'-dioxide compounds(IVa, IVb)were obtained.
