O[C:2]1[C:7]([N+:8]([O-:10])=[O:9])=[CH:6][C:5]([CH2:11][CH:12]([CH3:14])[CH3:13])=[CH:4][N:3]=1.P(Cl)(Cl)([Cl:17])=O.[Na].C(=O)([O-])O>>[Cl:17][C:2]1[C:7]([N+:8]([O-:10])=[O:9])=[CH:6][C:5]([CH2:11][CH:12]([CH3:14])[CH3:13])=[CH:4][N:3]=1A mixture of 1.7 g of 2-hydroxy-3-nitro-5-(2-methylpropyl)pyridine (starting material D4) and 15 ml of phosphorous oxychloride is heated under reflux to 120° C. for two hours. After cooling the mixture is carefully added to ice/water, then neutralized with sodium-hydrogencarbonate and extracted three times with ethylacetate. The combined organic phases are evaporated to dryness and the residue is chromatographed on a silica gel column (ethylacetate/petroleum ether 1:15). Concentration of the chromatographically pure fractions gives 1.17 g of the title compound as an orange oil.
Wird geladen…