2-Amino-3-nitro-6-picoline

1824-81-3

21901-29-1

Example 7: Synthesis of 6-(1-vinylimino)-2-carbamoyl-3-nitropyridine (Compound V) Reagents: (i) HNO3/H2SO4; (ii) NaNO2; (iii) POCl3; (iv) Na2Cr2O7; (v) SOCl2, followed by treatment with NH4OH; (vi) aziridine. Steps for the synthesis of compound 24: 1. cool concentrated sulfuric acid (100 mL) in an ice bath and slowly add raw compound 23 (30 g, 0.28 mol), keeping the temperature at 0°C. 2. 42 mL of a mixture of concentrated sulfuric acid (98%) and concentrated nitric acid (72%) with a volume ratio of 1:1 was added slowly dropwise, maintaining the reaction temperature at 0 °C. The reaction was allowed to stand for 12 hours after 1 hour. 3. The reaction mixture was poured into 2 L of ice-water mixture, the pH was adjusted to 7 with a strong aqueous alkali solution and filtered. 4. The filter cake was dried to obtain 54 g of crude product. 5. The crude product was subjected to hydrodistillation to obtain a bright yellow liquid. 6. The distillate was extracted with ethyl acetate and subsequently recrystallized in ethanol to give 12.5 g of compound 24 with a melting point of 156.5-158.5 °C (ethyl acetate) in 29% yield.