反应详情

5-(3-Amino-2-hydroxy-phenyl)-furan-2-carboxylic acid hydrobromide 9c (333 mg, 1.1 mmol) was dissolved in hydrochloric acid (3.7 mL, 1 mol/L) upon cooling by an ice-water bath, followed by dropwise addition of 1.5 mL of aqueous sodium nitrite (85 mg, 1.22 mmol). After the mixture was reacted for 20 minutes, 5-methyl-2-(3-methyl-indan-5-yl)-2,4-dihydro-pyrazol-3-one 38c (228 mg, 1.0 mmol), sodium bicarbonate (1.4 g, 16.67 mmol) and 3 mL of ethanol were added successively. The reaction mixture was reacted overnight at room temperature. The reaction was monitored by TLC until the disappearance of the starting materials. The mixture was filtered and 20 mL of water was added to the filter cake. The mixture was adjusted to pH 3˜4 with concentrated hydrochloric acid. The mixture was filtered and the filter cake was dried and purified by silica gel column chromatography to obtain the title compound 5-(2-hydroxy-3-{N′-[3-methyl-1-(3-methyl-indan-5-yl)-5-oxo-1,5-dihydro-pyrazol-4-ylidene]-hydrazino}-phenyl)-furan-2-carboxylic acid 44 (110 mg, yield 24.0%) 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 overnight at room temperature
4. filtrationThe mixture was filtered
5. addition20 mL of water was added to the filter cake
6. filtrationThe mixture was filtered
7. customthe filter cake was dried
8. custompurified by silica gel column chromatography