Ciba Specialty Chemicals Corporation

Andrew B Naughton

Mervin Gale Wood

Deborah DeHessa

Joseph Suhadolnik

Stephen D Pastor

Robert E Detlefsen

Anthony DeBellis

Joseph E Babiarz

Jacqueline Lau

Rong Xiong

Jerome Sanders

Compounds of formula I or II where R is an aryl moiety, such as phenyl, naphthyl or biphenylyl, or is phenyl substituted by one or more trifluoromethyl, bromo or cyano, and Eand Eare independently hydrogen, alkyl, aralkyl and the like are prepared by reaction of a benzotriazole substituted on the 5-position of the benzo ring by a halogen atom with a arylboronic acid or ester in the presence of a transition-metal catalyst, such as palladium (II) diacetate. The benzotriazole compounds of formula I are particularly efficacious as stabilizers for automotive coatings and candle wax.

Substituted 5-aryl-2-(2-hydroxyphenyl)-2H-benzotriazole UV absorbers, compositions stabilized therewith and process for preparation thereof

where R is an aryl moiety, such as phenyl, naphthyl or biphenylyl, or is phenyl substituted by one or more trifluoromethyl, bromo or cyano, and Eand Eare independently hydrogen, alkyl, aralkyl and the like are prepared by reaction of a benzotriazole substituted on the 5-position of the benzo ring by a halogen atom with a arylboronic acid or ester in the presence of a transition-metal catalyst, such as palladium (II) diacetate. The benzotriazole compounds of formula I are particularly efficacious as stabilizers for automotive coatings and candle wax.

Substituted 5-aryl-2-(2-hydroxyphenyl)-2h-benzotriazole UV absorbers, compositions stabilized therewith and process for preparation thereof

Provided is a process for preparing 2H-benzotriazole UV absorbers containing a perfluoroalkyl moiety at the 5-position of the benzoic ring, for example a trifluoromethyl group, which involves digitizing the perfluoroalkyl substituted o-nitroaniline using concentrated sulfuric acid plus sodium nitrite or nitrosylsulfuric acid to form the corresponding monoazobenzene intermediate via the diazonium salt intermediate which is reduced to the corresponding 5-perfluoroalkyl substituted 2H-benzotriazole UV absorber compound by conventional reduction means. Also provided is a novel one-pot, multiphase reaction for the preparation of 2(2-nitrophenylazo) substituted phenols, which are precursors for 2H-benzotriazole UV absorbers.

Processes for the preparation of benzotriazole UV absorbers

Provided is a process for preparing 2H-benzotriazole UV absorbers containing a perfluoroalkyl moiety at the 5-position of the benzo ring, for example a trifluoromethyl group, which involves diazotizing the perfluoroalkyl substituted o-nitroaniline using concentrated sulfuric acid plus sodium nitrite or nitrosylsulfuric acid to form the corresponding monoazobenzene intermediate via the diazonium salt intermediate which is reduced to the corresponding 5-perfluoroalkyl substituted 2H-benzotriazole UV absorber compound by conventional reduction means. Also provided is a novel one-pot, multiphase reaction for the preparation of 2(2-nitrophenylazo) substituted phenols, which are precursors for 2H-benzotriazole UV absorbers.

A process for preparing 2H-benzotriazole UV absorbers containing a perfluoroalkyl moiety at the 5-position of the benzo ring, preferably a trifluoromethyl group, involves diazotizing the perfluoroalkyl substituted o-nitroaniline using concentrated sulfuric acid plus sodium nitrite or preferably nitrosylsulfuric acid to form the corresponding monoazobenzene intermediate via the diazonium salt intermediate which is reduced to the corresponding 5-perfluoroalkyl substituted 2H-benzotriazole UV absorber compound by conventional reduction means.

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Mobile, AL, United States of America

Andrew B Naughton