反应详情

5-(3-Amino-2-hydroxy-phenyl)-furan-2-carboxylic acid hydrobromide 4g (292 mg, 0.98 mmol) was dissolved in 3.3 mL of 1M hydrochloric acid upon cooling by an ice-water bath, followed by dropwise addition of 1.3 mL of sodium nitrite solution (74 mg, 1.07 mmol). After the mixture was stirred for 20 minutes, 5-methyl-2-(5,6,7,8-tetrahydro-naphthalen-2-yl)-2,4-dihydro-pyrazol-3-one 7c (200 mg, 0.88 mmol) was added. The mixture was adjusted to pH 8˜9 by batch addition of sodium bicarbonate solution (1.226 g, 14.6 mmol). The generated bubbles were quenched with 2 mL of ethanol. The reaction mixture was warmed up to room temperature and reacted overnight. The mixture was filtered and the filter cake was dissolved in 20 mL of water. After mixing well, the mixture was adjusted to pH 3-4 with concentrated hydrochloric acid, filtered and dried. The crude product was purified by HPLC to obtain the title compound (Z)-5-(2-hydroxy-3-{N′-[3-methyl-5-oxo-1-(5,6,7,8-tetrahydro-naphthalen-2-yl)-1,5-dihydro-pyrazol-4-ylidene]-hydrazino}-phenyl)-furan-2-carboxylic acid 7d (160 mg, yield 39.8%) as a red solid.

1. temperatureupon cooling by an ice-water bath
2. customThe generated bubbles were quenched with 2 mL of ethanol
3. customreacted overnight
4. filtrationThe mixture was filtered
5. dissolutionthe filter cake was dissolved in 20 mL of water
6. additionAfter mixing well
7. filtrationfiltered
8. customdried
9. customThe crude product was purified by HPLC