4-Chloro-2,3-diMethyl-5-nitropyridine synthesis

Yield:-

Reaction Conditions:

with phosphorus pentachloride;trichlorophosphate at 20;Heating / reflux;

Steps:

264.4

2,3-Dimethyl-4-hydroxy-5-nitropyridine (26.8 g, 0.16 mol) prepared in Step 3 was added to 85 ml of phosphorus oxychloride. Phosphorus pentachloride (33.3 g, 0.16 mol) was added to the reaction mixture, which was then refluxed under stirring for 2 hours. The reaction mixture was left overnight at room temperature, added to ice water, brought to pH 5 with 28 % ammonium hydroxide, and then extracted with ether. The separated organic layer was dried on anhydrous magnesium sulfate and then con? centrated to give 28.3 g of the titled compound.[760] ¹ H-NMR (CDCl ) δ 2.47(s, 3H), 2.66(s, 3H), 8.77(s, IH)

References:

WO2006/38773,2006,A1 Location in patent:Page/Page column 55