反应详情

3′-Amino-2′-hydroxy-biphenyl-3-carboxylic acid hydrobromide 1f (172 mg, 0.56 mmol) was dissolved in 1.9 mL of 1 N hydrochloric acid upon cooling by an ice-water bath, followed by dropwise addition of 0.7 mL of aqueous sodium nitrite (42 mg, 0.61 mmol) and 5-methyl-2-(1,1,3,3-tetramethyl-indan-5-yl)-2,4-dihydro-pyrazol-3-one 19d (135 mg, 0.5 mmol). The mixture was adjusted to pH 8˜9 by batch addition of saturated sodium bicarbonate (700 mg, 8.33 mmol) followed by addition of 2 mL of ethanol. The reaction mixture was warmed up to room temperature overnight. The reaction was monitored by TLC until the disappearance of the starting materials. 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 2′-hydroxy-3′-{N′-[3-methyl-5-oxo-1-(1,1,3,3-tetramethyl-indan-5-yl)-1,5-dihydro-pyrazol-4-ylidene]-hydrazino}-biphenyl-3-carboxylic acid 19 (75 mg, yield 29.4%) as a red solid.

1. temperatureupon cooling by an ice-water bath
2. filtrationThe mixture was filtered
3. dissolutionthe filter cake was dissolved in 20 mL of water
4. additionAfter mixing well
5. filtrationfiltered
6. customdried
7. customThe crude product was purified by HPLC