2-Pyridinecarboxylic acid, 1,6-dihydro-6-oxo-, hydrazide synthesis

Yield:956386-24-6 0.34 g

Reaction Conditions:

with hydrazine hydrate monohydrate in methanol at 80; for 2 h;

Steps:

1.5 (5) Preparation of intermediate 6-hydroxypyridinylhydrazide

The 6-hydroxypyridine-2-carboxylic acid (0.556g, 4mmol) was dissolved in a methanol solvent (20mL), and under stirred conditions, 98% concentrated sulfuric acid (about 1mL) was added dropwise as a catalyst. Then, the reaction system was heated to 80 ° C after reflux stirring for 4 hours, the reaction material was cooled to room temperature, the solvent was removed by reduced pressure distillation, the crude product was extracted by using dichloromethane, separated, anhydrous magnesium sulfate dried, and the solvent was removed by vacuum distillation to give the crude product methyl 2-hydroxypyridine (0.565g, 92%). Then, the crude product methyl 2-hydroxypyridine (0.46g, 3 mmol) and hydrazine hydrate (0.75 g, 15 mmol) were dissolved in a methanol solvent (10 mL), and continued to be heated at 80 °C and stirred for 2 hours. After the reaction was completed, the reaction material was cooled to room temperature, the solvent was removed by distillation under reduced pressure, and 6-hydroxypyridylhydrazide was obtained by column chromatography (ethyl acetate: petroleum ether = 1:4) to 0.34g, with a yield of 80%.

References:

CN113979998,2022,A Location in patent:Paragraph 0021; 0054; 0072-0075