Реакция #54397

Уравнение реакции

4,4-dibromo-3-methyl-1-(4-sulfophenyl)-2-pyrazolin-5-one

2-hydrazinopyridine

HCl

→

3-Methyl-4-(2-pyridylazo)-1-(4-sulfophenyl)-2-pyrazolin-5-one

Растворители

water

Условия реакции

Обработка

1. 1
   ТемператураThe mixture was heated on the steam bath a total of six hours
2. 2
   ТемператураAfter a few minutes of heating
3. 3
   ТемператураThe mixture was cooled somewhat
4. 4
   Другоеthe orange solid was isolated by suction filtration
5. 5
   ПромывкаAfter washing once with tetrahydrofuran, twice with ether
6. 6
   Другоеdrying

Методика

41.0 g (0.10 mole) of 4,4-dibromo-3-methyl-1-(4-sulfophenyl)-2-pyrazolin-5-one, which can be prepared according to the method of Machiele, U.S. Pat. No. 3,952,009 (Example 1), and 16.0 g (0.15 mole) of 2-hydrazinopyridine were combined in 180 ml of water. The mixture was heated on the steam bath a total of six hours. After a few minutes of heating, the solution goes to a very thick slurry. The mixture was cooled somewhat, 10 ml of concentrated HCl were added, and the orange solid was isolated by suction filtration. After washing once with tetrahydrofuran, twice with ether, and drying, the yield of dye was 17.8 g (50 percent).

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