反应详情

3′-Amino-2′-hydroxy-biphenyl-3-carboxylic acid hydrobromide 1f (344 mg, 1.11 mmol) was dissolved in 3.7 mL of hydrochloric acid (1 N) upon cooling by an ice-water bath, followed by addition of 1.5 mL of aqueous sodium nitrite (85 mg, 1.22 mmol) and 5-methyl-2-(3-methyl-indan-5-yl)-2,4-dihydro-pyrazol-3-one 38f (228 mg, 1 mmol). The mixture was adjusted to pH 8 with saturated aqueous sodium bicarbonate, 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 30 mL of water was added to the filter cake. The mixture was adjusted to pH 3˜4 with concentrated hydrochloric acid and filtered. The filter cake was dried and then 10 mL of a solvent mixture of dichloromethane/methanol (V:V=50:1) was added. Upon completion of the addition, the mixture was stirred for 1 hour. Then the mixture was filtered and the filter cake was washed with dichloromethane (2 mL×3) and dried to obtain the title compound 2′-hydroxy-3′-{N′-[3-methyl-1-(3-methyl-indan-5-yl)-5-oxo-1,5-dihydro-pyrazol-4-ylidene]-hydrazino}-biphenyl-3-carboxylic acid 38 (300 mg, yield 64.1%) as a yellow solid.

1. temperatureupon cooling by an ice-water bath
2. filtrationThe mixture was filtered
3. addition30 mL of water was added to the filter cake
4. filtrationfiltered
5. customThe filter cake was dried
6. addition10 mL of a solvent mixture of dichloromethane/methanol (V:V=50:1)
7. additionwas added
8. additionUpon completion of the addition
9. filtrationThen the mixture was filtered
10. washthe filter cake was washed with dichloromethane (2 mL×3)
11. customdried