25729-32-2

Upstream product

• 88-74-4 2-nitro-aniline 
• 150-76-5 4-methoxy-phenol 
• 119-66-4 2-nitrobenzenediazonium chloride 
• 22358-67-4 4-methoxy-2-(2'-nitrophenylazo)phenol 

Relevant academic research and scientific papers

Preparation of 2-aryl-2H-benzotriazoles by zinc-mediated reductive cyclization of o-nitrophenylazophenols in aqueous media without the use of organic solvents

Zinc powder-mediated reductive cyclization of o-nitrophenylazophenols in alkaline solution affords the corresponding 2-aryl-2H-benzotriazoles in high yields under mild reaction conditions. No organic solvents are used in the reaction and only minimal amounts in the work-up.

Method for producing 2-(2'-hydroxy 5'-methoxyphenyl)benzotriazole

The invention relates to a method for preparing a benzotriazole ultraviolet light absorber, in particular to a method for preparing 2-(2'-hydroxyl 5'-methoxyphenyl) benzotriazole, which comprises thefollowing steps: reacting o-nitroaniline with alkali metal nitrite under the conditions of inorganic strong acidity and low temperature to synthesize diazonium salt; dissolving p-methoxyphenol in an aliphatic solvent under an alkaline condition, and coupling p-methoxyphenol with diazonium salt under a low-temperature condition to obtain an azo compound; producing a semi-reduction product from theazo compound under an alkaline condition under the action of a reducing agent; and reacting the semi-reduction product in an organic solvent under the action of a metal reducing agent to obtain the product. Due to the adoption of the preparation method, the preparation of the ultraviolet light absorber 2-(2'-hydroxyl 5'-methoxyphenyl)benzotriazole is simpler, the content is high, the yield is high, no pollution is caused, and the barrier rate is high.

OPTICAL MATERIAL COMPRISING A RED-SHIFTED BENZOTRIAZOLE UV ABSORBER

The present invention relates to an eyeglass lens comprising a substrate made of an optical material comprising a polymer matrix and at least one 2-(2-hydroxy-5-R1-phenyl)benzotriazole, in which R1 is a resonant group, the optical tr

SUBSTITUTED BENZOTRIAZOLE PHENOLS

Benzotriazole phenols with substituents either ortho to the phenol hydroxyl group and/or para to the phenol hydroxyl group can be prepared from the unsubstitued benzotriazole phenol by coupling reactions. The ortho substituent group can be a simple alkoxy

Preparation of Some 2-(Methoxyphenyl)-2H-benzotriazoles and the Corresponding Hydroxyphenyl Compounds

The reaction of several substituted o-nitronitrosobenzenes with o- and p-anisidine, and 2,4-dimethoxyaniline in acetic acid gives in good yield the corresponding o-nitroazobenzenes which are readily reduced with thiourea dioxide (formamidinesulfinic acid) to the corresponding 2-(methoxyphenyl)-2H-benzotriazoles, demethylation of which furnished the corresponding 2-(hydroxyphenyl)-2H-benzotriazoles.Demethylation of the dimethoxy derivatives was best accomplished with boron tribromide in methylene chloride, the methoxy group located ortho to the benzotriazole ring beingdemethylated more readily than is the para-methoxy group.The reaction of 0-nitroazobenzenes containing a methoxy group with hydrobromic acid in acetic acid results in cleavage of the azo bond and also partial bromination to give o-nitroaniline and some of its brominated derivatives.

High molecular weight piperidine derivatives as UV stabilizers

Substituted high molecular weight hindered spiropiperidine compounds and polymer compositions stabilized by these compounds. The spiropiperidine compounds are prepared by reacting hindered 4-piperidinone hydrochloride with an activated benzene, such as resorcinol, in an acid medium.