94109-79-2

Usage

Functionality

UV absorber and light stabilizer

Applications

Plastics, coatings, adhesives, textiles

Purpose

Protection against UV radiation, degradation, and discoloration

Mechanism

Absorbs and converts harmful UV radiation into harmless heat

Thermal stability

Excellent

Compatibility

Wide range of materials

Upstream product

• 486-25-9 9-fluorenone 
• 52184-19-7 2-Nitro-2'-hydroxy-3',5'-di-tert-pentyl-azobenzene 
• 71-36-3 butan-1-ol 
• 52184-19-7 2,4-Bis-(1,1-dimethyl-propyl)-6-(2-nitro-phenylazo)-phenol 
• 52184-19-7 2,4-bis(1,1-dimethylpropyl)-6-(2'-nitrophenylazo)phenol 

Downstream Products

• 25973-55-1 tinuvin 328 

Relevant academic research and scientific papers

Electrochemical synthesis of 2-aryl-2H-benzotriazoles and their N-oxides by controlled potential cathodic electrolysis

Using a divided cell, reductive cyclizations of o-nitrophenylazo dyes (1) toward 2-aryl-2H-benzotriazole-1-oxides (2) or 2-aryl-2H-benzotriazoles (3) were successfully accomplished by the controlled potential cathodic electrolysis reactions. 1 was transformed to 2 under neutral conditions while 1 was transformed to 3 under basic conditions.

Fluorenol catalyzed reduction of o-nitroazobenzenes and 2-aryl-2H-benzotriazole-N-oxides

A process for producing 2-aryl-2H-benzotriazole by reducing an o-nitroazobenzene with a saccharide having an aldehyde group as a reducing agent in the presence of fluorenol as a catalyst and a base in solution. The reaction is conducted at a temperature of from about 60° C. to about 80° C. The reaction time and amount of catalyst is significantly reduced compared to the use of an aromatic ketone catalyst. The invention also provides a method for producing 2-aryl-2H-benzotriazole by reducing a 2-aryl-2H-benzotriazole-N-oxide intermediate with a saccharide having an aldehyde group as a reducing agent, in the presence of fluorenol under similar conditions.

Method for preparing 2-phenylbenzotriazoles

This invention relates to a method for preparing a 2-phenylbenzotriazole of formula I, STR1 (wherein R1 represents hydrogen or chlorine atom, a lower alkyl group having a carbon number of 1 to 4, a lower alkoxy group having a carbon number of 1 to 4, carboxyl group, or sulfonic acid group; R2 represents hydrogen or chlorine atom, a lower alkyl group having a carbon number of 1 to 4, or a lower alkoxy group having a carbon number of 1 to 4; R3 represents hydrogen or chlorine atom, an alkyl group having a carbon number of 1 to 12, a lower alkoxyl group having a carbon number of 1 to 4, phenyl group, a phenyl group substituted with an alkyl group having a carbon number of 1 to 8, phenoxy group, or a phenylalkyl group, the alkyl part of which has a carbon number of 1 to 4; R4 represents hydrogen or chlorine atom, hydroxyl group, or a lower alkoxy group having a carbon number of 1 to 4; and R5 represents hydrogen atom, an alkyl group having a carbon number of 1 to 12, or a phenylalkyl group, the alkyl part of which has a carbon number of 1 to 4), which comprises reducing an o-nitroazobenzene of formula III, STR2 (wherein R1, R2, R3, R4 and R5 are as defined above) with at least one selected from the group consisting of primary and secondary alcohol reducing agents in the presence of an aromatic ketone catalyst and base. This invention further relates to a method for preparing a 2-phenylbenzotriazole of formula I as defined above, which comprises reducing 1 mole 2-phenylbenzotriazole-N-oxide of formula II, STR3 (wherein R1, R2, R3, R4 and R5 are as defined above) with 0.4 to 0.7 mole primary alcohol and/or 0.8 to 1.4 mole secondary alcohol in the presence of an aromatic ketone catalyst and base. This invention still further relates to a method for preparing a 2-phenylbenzotriazole-N-oxide of formula II as defined above, which comprises reducing 1 mole o-nitroazobenzene of formula III as defined above with 0.4 to 0.7 mole primary alcohol and/or 0.8 to 1.4 mole secondary alcohol in the presence of an aromatic ketone catalyst and base.

Method for preparing 2-phenylbenzotriazoles and 2-phenylbenzotriazole-N-oxides

This invention relates to a method for preparing a 2-phenylbenzotriazole of formula I, STR1 (wherein R1 represents hydrogen or chlorine atom, a lower alkyl group having a carbon number of 1 to 4, a lower alkoxyl group having a carbon number of 1 to 4, carboxyl group, or sulfonic acid group; R2 represents hydrogen or chlorine atom, a lower alkyl group having a carbon number of 1 to 4, or a lower alkoxyl group having a carbon number of 1 to 4; R3 represents hydrogen or chlorine atom, an alkyl group having a carbon number of 1 to 12, a lower alkoxyl group having a carbon number of 1 to 4, phenyl group, a phenyl group substituted with an alkyl group having a carbon number of 1 to 8, phenoxy group, or a phenylalkyl group, the alkyl part of which has a carbon number of 1 to 4; R4 represents hydrogen or chlorine atom, hydroxyl group, or a lower alkoxyl group having a carbon number of 1 to 4; and R5 represents hydrogen atom, an alkyl group having a carbon number of 1 to 12, or a phenylalkyl group, the alkyl part of which has a carbon number of 1 to 4), which comprises reducing an o-nitroazobenzene of formula III, STR2 (wherein R1, R2, R3, R4 and R5 are as defined above) with an aldehyde reducing agent in the presence of an aromatic ketone catalyst and base. This invention further relates to a method for preparing a 2-phenylbenzotriazole of formula I as derfined above, which comprises reducing 1 mole 2-phenylbenzotriazole-N-oxide of formula II, STR3 (wherein R1, R2, R3, R4 and R5 are as defined above) with 1 to 4 mole aldehyde in the presence of an aromatic ketone catalyst and base. This invention still further relates to a method for preparing a 2-phenylbenzotriazole-N-oxide of formula II as defined above, which comprises reducing 1 mole o-nitroazobenzene of formula III as defined above with 1 to 2 mole aldehyde in the presence of an aromatic ketone catalyst and base.

Method for preparing 2-phenylbenzotriazoles and 2-phenylbenzotriazole-N-oxides

A method for preparing a 2-phenylbenzotriazole of formula I wherein R1 is H, Cl, C1-4alkyl, C1-4alkoxy, COOH or SO3H; R2 is H, Cl, C1-4alkyl or C1-4alkoxy; R3 is H, Cl, C1-12alkyl, C1-4alkoxy, phenyl, (C1-8alkyl)phenyl, phenoxy or phenyl(C1-4alkyl); R4 is H, Cl, OH or C1-4alkoxy; and R5 is H, C1-12alkyl or phenyl(C1-4alkyl), comprises reducing a nitroazobenzene of formula III = wherein R1, R2, R3, R4 and R5 are as defined above, with a saccharide in the presence of a hydrogen transfer catalyst and base. This method can be conducted in one or two steps. The individual steps, the first from the nitroazobenzene to a 2-phenylbenzotriazole-N-oxide of formula II and the second (II→I) are independent aspects of the invention.

The Reduction of Some o-Nitrophenylazo Dyes with Thiourea S,S-Dioxide (Formamidinesulfinic Acid): a General Synthesis of 2-Aryl-2H-benzotriazoles and Their 1-Oxides

Thiourea S,S-dioxide (formamidinesulfinic acid) reacts with o-nitrophenylazo dyes in ethanolic alkali to give, depending on the reaction conditions, either the corresponding 2-aryl-2H-benzotriazoles or their 1-oxides.The reagent is particularly effective for preparing in high yield 2-(2'H-benzotriazol-2'-yl)phenols, which are important ultraviolet absorbers.The corresponding reductions involving ammonium sulfide and sodium dithionite were also examined.The former reagent was unsatisfactory; the latter reagent behaved erratically and was a less effective reducing reagent than thiourea dioxide.Nevertheless, conditions were established whereby sodium dithionite furnished the 2-(2'H-benzotriazol-2'-yl)phenols in high yield and purity.