反应详情

To a solution of potassium ethoxide (2.05 g, 24.3 mmol) in diethyl ether (70 mL) and ethanol (10 mL) under an argon atmosphere was added diethyl oxalate (3.3 mL, 24.3 mmol) and the reaction stirred at rt for 15 min. A solution of 2-bromo-4-methyl-5-nitropyridine (Preparation 24, 4.8 g, 22.1 mmol) in diethyl ether (20 mL) was added to the reaction mixture giving an immediate black precipitate. The reaction was allowed to stir at rt for 6 h, then cooled to 0° C. and filtered to give a black solid. The solid was dissolved in water (250 mL) and acidified to pH 4 with acetic acid resulting in formation of a red precipitate. The solid was collected and dried to give the title compound as a red solid. δH (d6 DMSO): 1.16 (3H, t), 4.01 (2H, q), 6.55 (1H, s), 7.92 (1H, s), 8.96 (1H, s).

1. customgiving an immediate black precipitate
2. stirringto stir at rt for 6 h
3. temperaturecooled to 0° C.
4. filtrationfiltered
5. customto give a black solid
6. customThe solid was collected
7. customdried