Process for the preparation of bromo-functionalized benzotriazole UV absorbers
AssigneeCouncil of Scientific and Industrial Research
InventorsParagkumar Nathalal Thanki, Raj Pal Singh
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Abstract
The invention also pertains to a process for their preparation of bromo functionalised benzotriazole UV absorber of the general formula 1 wherein R1 is hydrogen, tert-butyl; X1 is selected the group consisting of hydrogen, halogen, tert-butyl and C1 to C12 alkoxy by reacting a benzotriazole having formula 2 wherein R1 is hydrogen, tert-butyl; X1 is selected the group consisting of hydrogen, halogen, tert-butyl and C1 to C12 alkoxy with bromine in the presence of a free radical initiator in a non-polar solvent to produce a bromo functionialized benzotriazole.
Claims3
A process for the preparation of bromo-functionalized benzotriazole UV absorber of formula 1
- wherein R1 is selected from hydrogen and tert-butyl;
- X1 is selected from the group consisting of hydrogen, halogen, tert-butyl and C1 to C12 alkoxy, said process comprising reacting benzotriazole of formula 2
- wherein R1 is selected from hydrogen and tert-butyl;
- X1 is selected the group consisting of hydrogen, halogen, tert-butyl and C1 to C12 alkoxy, with bromine in presence of a non-polar solvent and a free radical initiator selected from the group consisting of 2, 2′-azobisisobutyronitrile, 1,1′-azobis-2-cyclopropylpropionitrile, 2,2′-azobis-2-cyclopropylpropionitrile, 2,2′-azobis-2,4,4-trimethylvalaronitrile, 1,1′-azobis-1-cyclooctane-nitrile, and azo-bis-(1-carbomethoxy-3-methylpropane) at a temperature ranging between 45 to 52° C. for a period of 4 to 10 hours, bringing the reaction mixture to ambient temperature, separating the solvent and purifying the product by recrystallization.
Dependencies are inferred from the claim text.