反应详情

A solution of 3′-{N′-[1-(3,4-dimethylphenyl)-3-methyl-5-oxo-1,5-dihydro-pyrazol-4-ylidene]hydrazino}-2′-methoxybiphenyl-3-carboxylic acid (4 g), prepared as in Example 3, in 48% aqueous hydrobromic acid (35 mL) and glacial acetic acid (35 mL) was stirred and heated under reflux for about 60 hours. The reaction mixture was concentrated under vacuum to a thick residue. Water (40 mL) was added and basified to pH 7-8 using saturated solution of sodium bicarbonate (20 mL). The mixture was filtered to give an orange solid, which was washed with water (25 mL) and dried in an oven at 55° C. about to about 60° C. for about 12 hours.

1. temperatureheated
2. temperatureunder reflux for about 60 hours
3. concentrationThe reaction mixture was concentrated under vacuum to a thick residue
4. additionWater (40 mL) was added
5. filtrationThe mixture was filtered
6. customto give an orange solid, which
7. washwas washed with water (25 mL)
8. customdried in an oven at 55° C. about to about 60° C. for about 12 hours