A process for the preparation of compounds of formula (I): wherein the general symbols are as defined in claim 1, which comprises reacting a compound of formula (V): wherein R
1
, R
2
, R
3
, R
4
, R
5
, R
6
, R
7
, R
8
, R
9
and R
18
are as defined in claim 1, and R
18
is especially nitro, chlorine or bromine, with an azide compound of formula (IX): wherein M and n are as defined in claim 1, especially with sodium azide.
Process for the preparation of 5-perfluoroalkyl substituted benzotriazole UV absorbers
申请人:Ciba Specialty Chemicals Corporation
公开号:US06353113B1
公开(公告)日:2002-03-05
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.
Processes for the preparation of benzotriazole UV absorbers
申请人:——
公开号:US20020035175A1
公开(公告)日:2002-03-21
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.
[EN] NOVEL PROCEDURE FOR THE FORMATION OF 2H-BENZOTRIAZOLE BODIES AND CONGENERS<br/>[FR] NOUVELLE PROCÉDURE POUR LA FORMATION DE CORPS 2H-BENZOTRIAZOLE ET DE CONGÉNÈRES
申请人:BASF SE
公开号:WO2020114936A1
公开(公告)日:2020-06-11
The present invention relates to a process for the preparation of 2H-benzotriazole compounds and congeners, novel 2H-benzotriazole compounds and congeners and their use as UV absorbers in coatings and bulk plastics.
Substituted 5-aryl-2-(2-hydroxyphenyl)-2H-benzotriazole UV absorbers, compositions stabilized therewith and process for preparation thereof
申请人:——
公开号:US20040192927A1
公开(公告)日:2004-09-30
Compounds of formula I or II
1
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 E
1
and E
2
are 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.