4-Methyl-5-nitro-2(1H)-pyridinone

Orange plates

Weigh the starting material 2-amino-4-methyl-5-nitropyridine 23 (10 g) in a 250 ml round bottom flask and 70 ml of concentrated HSynthesis of the compound 31 The compound 30 (17.4 g, 0.114 mol) was added into 300 mL of water, a concentrated sulphuric acid (30 mL) was slowly added with agitation and cooled to 0°C in an ice bath. Sodium nitrite (17.5 g, 0.254 mol) was dissolved in 35 mL of water and added slowly beneath the reaction liquid surface of the reaction system via a long stem funnel. The reaction was run at room temperature for 2 h and boiled up until the reaction ends which was marked by no further brown gas was emitted. The reaction liquid was poured into broken ice, filtered, and dried to obtain 11.15g of the compound 31 with a yield of 63.7percent. The melting point is 187.3-188.9°C (ethanol) (M.P. 186°C was reported in the reference)[J. Chem. Soc.. 1954, 2248 -2451].The product of step 1 (0.13 g, 0.77 mmol) was dissolved in a 0°C solution of HBr in acetic acid (33percent w/w, 5ml) and then stirred at 60°C for 2 h, cooled to room temperature and poured into diethyl ether (10ml). The crystalline precipitate that was filtered, washed with ether and dried 0.155 g (86percent) of 4-methyl-5-nitro-pyridin-2-ol.A solution of To a suspension OF 2-HYDROXY-4-METHYL-5-NITROPYRIDINE (LG, 6. 5MMOL) in dichloroethane (lOmL) was added a solution of phosphorus oxybromide (2.8g, 9.7mmol) in dichloroethane (LOML). The reaction mixture was heated under reflux for 4h, then cooled to rt and quenched with water (40mL). The layers were separated and the aqueous layer extracted into dichloromethane (2 x 30mL). The combined organics were dried (MGS04), concentrated IRA vacuo and chromatographed on silica gel eluting with dichloromethane to give the title compound as a pale yellow SOLID. 8H (CDCl3): 2.63 (3H, s), 7.52 (1H, s), 8.96 (1H, s).

Molecular Weight:154.12
XLogP3:-0.3
Hydrogen Bond Donor Count:1
Hydrogen Bond Acceptor Count:3
Exact Mass:154.03784206
Monoisotopic Mass:154.03784206
Topological Polar Surface Area:74.9
Heavy Atom Count:11
Complexity:272
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes