Process for the preparation of benozotriazoles and their polymers, and 2(2-hydroxy-5-isopropenylphenyl)2H-benzotriazole produced thereby

Patent · Tue Mar 14 04:00:00 EST 1989

OSTI ID:866877

Vogl, Otto ^[1]; Nir, Zohar ^[2]

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1. Brooklyn, NY
2. Beer Sheva, IL

The compound 2(2-hydroxy-5-isopropenylphenyl)2H-benzotriazole (2H5P) is produced by azo coupling of o-nitrophenyl diazonium chloride with p-hydroxyacetophenone, subjecting the resulting isolated azo compound to reductive cyclization with zinc in the presence of sodium hydroxide at a temperature of about 50.degree.-70.degree. C., acidifying the resulting mixture so as to produce (2(2-hydroxy-5-acetylphenyl)2H-benzotriazole (2H5A), acetylating the isolated 2(2-hydroxy-5-acetylphenyl)2H-benzotriazole (2H5A), so as to produce 2(2-acetoxy-5-acetylphenyl)2H-benzotriazole (2A5A), methylating the isolated 2(2-acetoxy-5-acetylphenyl(2H-benzotriazole (2A5A) with a methyl Grignard reagent and dehydrating the isolated reaction product with potassium hydrogen sulfate so as to produce 2(2-hydroxy-5-isopropenylphenyl)2H-benzotriazole (2H5P). The compound is used as a polymerizable ultra violet light stabilizer.

• Assignee: United States of America as represented by United States (Washington, DC)
• Patent Number(s): US 4812575
• Application Number: 06/537,219
• OSTI ID: 866877
• Country of Publication: United States
• Language: English

Related Subjects

-70
/999/
2-acetoxy-5-acetylphenyl
2-hydroxy-5-acetylphenyl
2-hydroxy-5-isopropenylphenyl
2a5a
2h-benzotriazole
2h5a
2h5p
50
acetylating
acidifying
azo
azo compound
benozotriazoles
chloride
compound
coupling
cyclization
degree
dehydrating
diazonium
grignard
grignard reagent
hydrogen
hydroxide
isolated
light
light stabilizer
methyl
methylating
mixture
o-nitrophenyl
p-hydroxyacetophenone
polymerizable
polymers
potassium
preparation
presence
process
produce
produced
product
reaction
reaction product
reagent
reductive
resulting
resulting mixture
sodium
sodium hydroxide
stabilizer
subjecting
sulfate
temperature
ultra
ultra violet
violet
violet light
zinc