反应详情

A solution of 1-methyl-5-nitro-1H-pyrazole-4-carbaldehyde (0.42 g, 2.8 mmol) in methanol (5 mL) was treated with silver (I) oxide (1.29 g, 5.6 mmol) followed by 5N potassium hydroxide (1.5 mL) in 5 mL of methanol and then refluxed for 16 hours. The mixture was cooled to room temperature and quenched with concentrated HCl (8 mL) and ethyl acetate. The mixture was filtered through a layer of celite and concentrated to give crude 1-methyl-5-nitro-1H-pyrazole-4-carboxylic acid: 1H NMR (300 MHz, CDCl3) δ 8.05 (s, 1H), 4.22 (s, 3H).

1. temperaturerefluxed for 16 hours
2. customquenched with concentrated HCl (8 mL) and ethyl acetate
3. filtrationThe mixture was filtered through a layer of celite and
4. concentrationconcentrated