反应详情

5-(3-Amino-2-hydroxy-phenyl)-furan-2-carboxylic acid methyl ester 54c (110 mg, 0.47 mmol) was dissolved in hydrochloric acid (1.6 mL, 1 mol/L) upon cooling by an ice-water bath, followed by dropwise addition of 0.6 mL of aqueous sodium nitrite (36 mg, 0.52 mmol). After the mixture was reacted for 20 minutes, 2-indan-5-yl-5-methyl-2,4-dihydro-pyrazol-3-one 1i (91 mg, 0.43 mmol) was added. The mixture was adjusted to pH 8˜9 with saturated aqueous sodium bicarbonate. The reaction mixture was reacted at room temperature for 24 hours. The reaction was monitored by TLC until the disappearance of the starting materials and quenched with ethanol. The mixture was filtered and the filter cake was dissolved in 15 mL of water. The mixture was adjusted to pH 3-4 with concentrated hydrochloric acid upon cooling by an ice-water bath. The mixture was filtered and the filter cake was purified by silica gel column chromatography to obtain the title compound 5-{2-hydroxy-3-[N′-(1-indan-5-yl-3-methyl-5-oxo-1,5-dihydro-pyrazol-4-ylidene)-hydrazino]-phenyl}-furan-2-carboxylic acid methyl ester 55 (137 mg, yield 70.3%) as a red solid.

1. temperatureupon cooling by an ice-water bath
2. customAfter the mixture was reacted for 20 minutes
3. customThe reaction mixture was reacted at room temperature for 24 hours
4. customquenched with ethanol
5. filtrationThe mixture was filtered
6. dissolutionthe filter cake was dissolved in 15 mL of water
7. temperatureupon cooling by an ice-water bath
8. filtrationThe mixture was filtered
9. customthe filter cake was purified by silica gel column chromatography