反应详情

4-(3-Amino-2-hydroxy-phenyl)-thiophene-2-carboxylic acid hydrobromide 19c (120 mg, 0.38 mmol) was dissolved in 2.7 mL of 1 M hydrochloric acid upon cooling by an ice-water bath, followed by dropwise addition of 0.45 mL of sodium nitrite solution (29 mg, 0.42 mmol). After the mixture was reacted for 20 minutes, 2-indan-5-yl-5-methyl-2,4-dihydro-pyrazol-3-one 1i (73 mg, 0.34 mmol) was added. The mixture was adjusted to pH 8 with saturated sodium bicarbonate solution followed by addition of 2 mL of ethanol. The reaction mixture was reacted overnight at room temperature. The mixture was filtered and the filter cake was added to 20 mL of water. The mixture was adjusted to pH 3-4 with concentrated hydrochloric acid and filtered. Then 5 mL of ethyl acetate was added to the filter cake and the mixture was stirred for 1 hour. The mixture was filtered and the filter cake was dried to obtain the title compound (Z)-4-{2-hydroxy-3-[N′-(1-indan-5-yl-3-methyl-5-oxo-1,5-dihydro-pyrazol-4-ylidene)-hydrazino]-phenyl}-thiophene-2-carboxylic acid 19d (45 mg, yield 28.7%) as a yellow 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. additionthe filter cake was added to 20 mL of water
6. filtrationfiltered
7. additionThen 5 mL of ethyl acetate was added to the filter cake
8. filtrationThe mixture was filtered
9. customthe filter cake was dried