preparation of 3-nitropyridine-2-carbaldehyde_industrial additives

preparation background and overview of 3-nitropyridine-2-carbaldehyde

3-nitropyridine-2-carbaldehyde, also called 2-formyl-3-nitropyridine, is a pharmaceutical intermediate that can be used to prepare 2-methyl-3 from 2-chloro-3-nitropyridine. – nitropyridine, obtained by oxidation of methyl group. 3-nitropyridine-2-carbaldehyde can be used to prepare a pyrro[2,3-c]pyridine derivative such as 1-allyl-2,3-dimethyl-1h-pyrrolo[2,3- c] pyridine-7-aldehyde, this type of compound has excellent proton pump inhibition and the ability to achieve reversible proton pump inhibition.

preparation of 3-nitropyridine-2-carbaldehyde

preparation step 1 of 3-nitropyridine-2-carbaldehyde, 2-methyl-3-nitropyridine di-n-butyl carbonate

place 2-chloro-3-nitropyridine (20g, 0.126mol), methylboronic acid (8.3g, 0.139mol), tetrakis(triphenylphosphine)palladium(0) (14.58g, 0.013mol) and a solution of potassium carbonate (52.3 g, 0.378 mol) in anhydrous 1,4-dioxane (100 ml) was refluxed for 2 days. the reaction mixture was cooled to room temperature, filtered and concentrated under reduced pressure. the resulting residue was purified by silica gel column chromatography (ethyl acetate/n-hexane=1/3, v/v) to obtain 14 g of the title compound as a brown oil. ¹h-nmr (mhz, cdcl₃) δ8.74 (d, 1h), 8.27 (d, 1h), 7.34 (t, 1h), 2.88 (s ,3h)

preparation step 2 of 3-nitropyridine-2-carbaldehyde, 2-formyl-3-nitropyridine

add 2-methyl-3-nitropyridine (10.155g, 72.46mmol) and selenium dioxide (8.84g, 79.71mmol) prepared in step 1 in 1,4-dioxane (80ml) the solution was refluxed for 2 days. the reaction mixture was cooled to room temperature, filtered, and concentrated under reduced pressure. the resulting residue was purified by silica gel column chromatography (ethyl acetate/n-hexane=1/2, v/v) to obtain 12.8 g of the title compound as a red oil. ¹h-nmr (mhz rubidium tetrafluoroborate, cdcl₃) δ10.27 (s, 1h), 9.00 (d, 1h), 8.28 (t, 1h) ,7.76(d,1h)

references

[1] [invented in china, authorized by china] cn200580029391.9 pyrro[2,3-c]pyridine derivatives and preparation method thereof