* All experimental methods are cited from the reference, please refer to the original source for details. We do not guarantee the accuracy of the content in the reference.
EXAMPLE 2 Preparation of 4-amino-5-chloro-1-phenylpyridazin-6-one (chloridazon) using bis(4-hydroxyphenyl) sulfone as catalyst In a 1 l stirring autoclave, 300 parts of water, 210 parts (3.09 mol) of 25percent strength ammonia, 36 parts (0.15 mol) of 4,5-dichloro-1-phenylpyridazin-6-one (purity: 99.7percent) and 37.5 parts (0.15 mol) of bis(4-hydroxyphenyl)sulfone were stirred at 130° C. for 8 hours. The pressure rose steadily to about 5 bar. After stirring overnight, the autoclave was depressurized to atmospheric pressure, with the excess ammonia being stripped off. After cooling to room temperature, the precipitated solid was filtered off, washed with water and dried at 50° C. in a vacuum drying oven. This gave 30.7 parts of 4-amino-5-chloro-1-phenylpyridazin-6-one having a purity of 99.9percent; this corresponds to a yield of 92.3percent of theory. The pH of the filtrate was adjusted to 1.4 using 60percent strength sulfuric acid and the precipitated bis(4-hydroxyphenyl)sulfone was filtered off and washed with water. This gave 53.5 parts of bis(4-hydroxyphenyl)sulfone having a water content of 30percent. This corresponds to 99.8percent of the amount of catalyst used.
90%
With ammonia In water
EXAMPLE 1 Preparation of 4-amino-5-chloro-1-phenylpyridazin-6-one (chloridazon) using bis(4-hydroxyphenyl)sulfone In a 250 ml stirring autoclave, 100 parts of water, 70 parts (1.03 mol) of 25percent strength ammonia, 12 parts (0.05 mol) of 4,5-dichloro-1-phenylpyridazin-6-one (purity: 99.7percent) and 12.5 parts (0.05 mol) of bis(4-hydroxyphenyl)sulfone were stirred at 130° C. for 8 hours. The pressure rose steadily to about 5 bar. After stirring overnight, the autoclave was depressurized to atmospheric pressure, with the excess ammonia being stripped off. After cooling to room temperature, the precipitated solid was filtered off, washed with water and dried at 50° C. in a vacuum drying oven. This gave 10.1 parts of 4-amino-5-chloro-1-phenylpyridazin-6-one having a purity of 98.8percent; this corresponds to a yield of 90percent of theory. The pH of the filtrate was adjusted to 1.5 using 60percent strength sulfuric acid and the precipitated bis(4-hydroxyphenyl)sulfone was filtered off, washed with water and dried. This gave 12.6 parts of bis(4-hydroxyphenyl)sulfone having a purity of 99.2percent; this corresponds to 100percent of the amount of catalyst used.
EXAMPLE 5 Preparation of 4-amino-5-chloro-1-phenylpyridazin-6-one (chloridazon) using 4,4'-dihydroxybenzophenone as catalyst In a 250 ml stirring autoclave, 100 parts of water, 70 parts (1.03 mol) of 25percent strength ammonia, 12 parts (0.05 mol) of 4,5-dichloro-1-phenylpyridazin-6-one (purity: 99.7percent) and 10.7 parts (0.05 mol) of 4,4'-dihydroxybenzophenone were stirred at 130° C. for 8 hours. The pressure rose steadily to about 4.5 bar. After stirring overnight, the autoclave was depressurized to atmospheric pressure, with the excess ammonia being stripped off. After cooling to room temperature, the precipitated solid was filtered off, washed with water and dried at 50° C. in a vacuum drying oven. This gave 10.2 parts of 4-amino-5-chloro-1-phenylpyridazin-6-one having a purity of 98.9percent; this corresponds to a yield of 91.1percent of theory. The pH of the filtrate was adjusted to 1.5 using 60percent strength sulfuric acid and the precipitated 4,4'-dihydroxybenzophenone was filtered off, washed with water and dried. This gave 10.9 parts of 4,4'-dihydroxybenzophenone having a purity of 98.3percent; this corresponds to 100percent of the amount of catalyst used.
Reference：
[1] Patent: US6538135, 2003, B1,
3
[ 100-02-7 ]
[ 1698-53-9 ]
[ 1698-60-8 ]
Yield
Reaction Conditions
Operation in experiment
92.2%
With ammonia In water
EXAMPLE 4 Preparation of 4-amino-5-chloro-1-phenylpyridazin-6-one (chloridazon) using 4-nitrophenol as catalyst In a 250 ml stirring autoclave, 100 parts of water, 70 parts (1.03 mol) of 25percent strength ammonia, 12 parts (0.05 mol) of 4,5-dichloro-1-phenylpyridazin-6-one (purity: 99.7percent) and 14.2 parts (0.1 mol) of 98percent-pure 4-nitrophenol were stirred at 130° C. for 8 hours. The pressure rose to about 4 bar. After stirring overnight, the autoclave was depressurized to atmospheric pressure, with the excess ammonia being stripped off. After cooling to room temperature, the precipitated solid was filtered off, washed with water and dried at 50° C. in a vacuum drying oven. This gave 10.3 parts of 4-amino-5-chloro-1-phenylpyridazin-6-one having a purity of 99.1percent; this corresponds to a yield of 92.2percent of theory. The pH of the filtrate was adjusted to 1.0 using 60percent strength sulfuric acid and the precipitated 4-nitrophenol was filtered off, washed with water and dried. This gave 14 parts of 4-nitrophenol having a purity of 98.1percent; this corresponds to 98.8percent of the amount of catalyst used.
Reference：
[1] Patent: US6538135, 2003, B1,
4
[ 1698-53-9 ]
[ 611-99-4 ]
[ 1698-60-8 ]
Reference：
[1] Patent: US6538135, 2003, B1,
5
[ 1698-53-9 ]
[ 80-09-1 ]
[ 1698-60-8 ]
Reference：
[1] Patent: US6538135, 2003, B1,
6
[ 1698-53-9 ]
[ 99-96-7 ]
[ 1698-60-8 ]
Reference：
[1] Patent: US4454318, 1984, A,
7
[ 1698-53-9 ]
[ 1698-60-8 ]
[ 1698-61-9 ]
Reference：
[1] Collection of Czechoslovak Chemical Communications, 1985, vol. 50, # 2, p. 492 - 502
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