Methanol → methyl 3-nitro-1H-pyrazole-5-carboxylate

Temperature

80 °C

Into a 100-mL round-bottom flask, was placed a solution of 5-nitro-1H-pyrazole-3-carboxylic acid (3.0 g, 19.1 mmol) in methanol (50 mL). Sulfuric acid (3 mL) was carefully added and the resulting solution was stirred overnight at 80° C., then concentrated under reduced pressure. The pH of the solution was carefully adjusted to 7 with aqueous sodium bicarbonate (sat.), then extracted with ethyl acetate (3×50 mL). The combined organic extracts were washed with brine (3×50 mL), dried (Na2SO4), filtered and concentrated under reduced pressure to obtain the title compound as a yellow solid (2.3 g, 70%).

1. customInto a 100-mL round-bottom flask, was placed
2. concentrationconcentrated under reduced pressure
3. extractionextracted with ethyl acetate (3×50 mL)
4. washThe combined organic extracts were washed with brine (3×50 mL)
5. dry with materialdried (Na2SO4)
6. filtrationfiltered
7. concentrationconcentrated under reduced pressure

ORD record

ord-6b146bf129e94a94a0783c19dc8411ac

Source dataset

uspto-grants-2016_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09428502B2