84755-47-5

Upstream product

• 84755-49-7 2-tert-Butyl-4-methyl-6-(2-nitro-phenylazo)-phenol 
• 2409-55-4 2-tert-Butyl-4-methylphenol 
• 88-74-4 2-nitro-aniline 

Downstream Products

• 23939-33-5 2-(2-hydroxy-3-tert-butyl-5-methylphenyl)-2H-benzotriazole 

Relevant academic research and scientific papers

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 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.

The Reduction of Some o-Nitrophenylazo Dyes with Glucose: A General Synthesis of 2-Aryl-2H-benzotriazole 1-Oxides

The reduction of some representative o-nitrophenylazo dyes in ethanolic alkali with glucose gives the corrsponding 2-aryl-2H-benzotriazole 1-oxides in excellent yield.These 1-oxides are rapidly reduced to the parent benzotriazoles at room temperature by means of zinc dust/ethanolic alkali.This method provides a convenient preparation for 5-chlorobenzotriazoles, which are otherwise readily dechlorinated by zinc dust under more vigorous conditions