反应详情

3′-[(2Z)-[1-(3,4-dimethylphenyl)-1,5-dihydro-3-methyl-5-oxo-4H-pyrazol-4-ylidene]hydrazino]-2′-hydroxy-[1,1′-biphenyl]-3-carboxylic acid, 8 g of crude orange solid, was dissolved at room temperature in THF (240 ml) in a 500 ml round bottom 3-necked flask under a nitrogen atmosphere. Ethanolamine (2.2 ml, 2 molar equivalents) was added via syringe over 5 minutes. The resulting dark red suspension was stirred at room temperature for 1.5 hours and the solid isolated by filtration, washed with THF (16 ml×2) and dried at 50° C. in a vacuum oven over night to yield 10.37 g of the title compound (more than quantitative yield due to residual solvent—approximately 2.4% w/w THF as determined by NMR, otherwise similar to Example 1).

1. customthe solid isolated by filtration
2. washwashed with THF (16 ml×2)
3. customdried at 50° C. in a vacuum oven over night