反应详情

5-(3-Amino-2-hydroxy-phenyl)-1,2,4-trimethyl-1H-pyrrole-3-carboxylic acid ethyl ester hydrobromide 6h (140 mg, 0.51 mmol) was dissolved in 1.76 mL of hydrochloric acid (1 N) followed by addition of 1 mL of aqueous sodium nitrite (39 mg, 0.56 mmol) and the mixture was stirred for 20 minutes upon cooling by an ice-water bath. 5-Methyl-2-(5,6,7,8-tetrahydro-naphthalen-2-yl)-2,4-dihydro-pyrazol-3-one 3i (105 mg, 0.46 mmol) was then added. The mixture was adjusted to pH 8 with saturated aqueous sodium bicarbonate, followed by addition of 1 mL of ethanol. The reaction 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 dried and then dissolved in dichloromethane. Then the mixture was washed with saturated brine and the organic layer was concentrated under reduced pressure. The residue was purified by silica gel column chromatography to obtain the title compound 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)-1,2,4-trimethyl-1H-pyrrole-3-carboxylic acid ethyl ester 6 (120 mg, 50.8%) as a red solid.

1. temperatureupon cooling by an ice-water bath
2. filtrationThe mixture was filtered
3. customthe filter cake was dried
4. dissolutiondissolved in dichloromethane
5. washThen the mixture was washed with saturated brine
6. concentrationthe organic layer was concentrated under reduced pressure
7. customThe residue was purified by silica gel column chromatography