2-(2-Hydroxyphenyl)-2H-benzotriazoles
# 2-(2-Hydroxyphenyl)-2H-benzotriazoles

2-(2-Hydroxyphenyl)-2H-benzotriazoles, also referred to as phenolic benzotriazoles, are an important class of UV absorbers comprising the benzotriazole building block.

## Structure

The molecules are composed of substituted benzotriazoles with a phenyl group in the 2-position, which carries a hydroxy group in the ortho-position.

Examples of 2-(2-hydroxyphenyl)-2H-benzotriazoles :

| Name | Acronym | $R^1$ | $R^2$ | $R^3$ |
| - | - | - | - | - |
| 2-(2H-Benzotriazol-2-yl)-4-methylphenol | UV-P | – | methyl | – |
| 2-(2H-Benzotriazol-2-yl)-4-tert-butylphenol | UV-PS | – | tert-butyl | – |
| 2-(2H-Benzotriazol-2-yl)-4,6-bis(2-phenyl-2-propanyl)phenol | UV-234 | (2-propanyl)phenol | (2-propanyl)phenol | – |
| 2-(2H-Benzotriazol-2-yl)-4,6-di-tert-butylphenol | UV-320 | tert-butyl | tert-butyl | – |
| 2-(5-Chloro-2H-benzotriazol-2-yl)-4-methyl-6-di-tert-butylphenol | UV-326 | tert-butyl | methyl | chlorine |
| 2-(5-Chloro-2H-benzotriazol-2-yl)-4,6-di-tert-butylphenol | UV-327 | tert-butyl | tert-butyl | chlorine |
| 2-(2H-Benzotriazol-2-yl)-4,6-di-tert-pentylphenol | UV-328 | tert-pentyl | tert-pentyl | – |
| 2-(2H-Benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol | UV-329 | – | 1,1,3,3-tetramethylbutyl | – |
| 2-(2H-Benzotriazol-2-yl)-6-(sec-butyl)-4-(tert-butyl)phenol | UV-350 | sec-butyl | tert-butyl | – |
| 2,2′-Methylenbis[6-(2H-benzotriazol-2-yl)-4-(2,4,4-trimethyl-2-pentanyl)phenol] | UV-360 | [dimer linked via methylene group] | 1,1,3,3-tetramethylbutyl | – |
| 2-(2H-Benzotriazol-2-yl)-6-(2-phenyl-2-propanyl)-4-(2,4,4-trimethyl-2-pentanyl)phenol | UV-928 | (2-propanyl)phenol | 1,1,3,3-tetramethylbutyl | – |

## Use

2-(2-hydroxyphenyl)-2H-benzotriazoles are used as UV stabilizers in lacquers and plastics.

