77896-55-0

Upstream product

• 77896-39-0 2-phenyl-2H-1,2,3-triazole 1-oxide 
• 108-24-7 acetic anhydride 
• 16293-42-8 2-phenyl-2,3-dihydro-[1,2,3]triazol-4-one 
• 118051-26-6 2-Phenyl-4-vinyloxy-2H-[1,2,3]triazole 
• 77896-38-9 2-phenylhydrazonoglyoxal 1-oxime 
• 100-63-0 phenylhydrazine 
• 20672-18-8 2-(phenylhydrazono)ethanal 

Downstream Products

• 16293-42-8 2-phenyl-2,3-dihydro-[1,2,3]triazol-4-one 

Relevant academic research and scientific papers

Reaction of 2-phenyl substituted 1,2,3-triazol 1-oxides with acylating agents. Preparation of hydroxy- halogen- hydroxymethyl- and chloromethyltriazoles

2-Phenyltriazol 1-oxides react with acetyl chloride producing acetoxy- and chloro-substituted triazoles.The substituents enter the 5 and the 4-position.When these are not accessible the substituents go to lateral positions and to the phenyl group producing acetoxymethyltriazoles and 2-halogenophenyl triazoles.Acetic anhydride reacts reluctantly while trifluoroacetic anhydride is more reactive producing trifluoroacetoxytriazoles.The reactions provide effective routes to hydroxy- and hydroxymethyltriazoles.Several mechanisms among which a cyclic one are operating.

HYDROXY-1,2,3-TRIAZOLES. I. SOME CHARACTERISTICS OF 4-HYDROXY-1,2,3-TRIAZOLES

Some chemical characteristics of 2-phenyl-4-hydroxy-1,2,3-triazole and the corresponding N-oxide were investigated.It was shown that the nitration and halogenation of these compounds takes place at position 5 of the triazole ring and alkylation and acylation take place at the hydroxyl group with the formation of ethers and esters.In vinyl exchange reactions with vinyl acetate the hydroxytriazole N-oxide gives the N-vinyl derivative, while the hydroxytriazole gives triazolyl vinyl ether.

INTRODUCTION OF SUBSTITUENTS INTO 5-MEMBERED AZA-HETEROAROMATICS

With emphasis on mono- and regio-selectively, methods for introduction of substituents at nitrogen and carbon atoms of 5-membered aza-heteroaromatics have been developed.The methods involve application of activation and of assistant groups for direction and protection.Activation has been achieved by the use of quaternary azolium ions and azol-N-oxides as reactive intermediates.If necessary, the N-oxides were further activated by alkylation or acylation.

Electrophilic and Nucleophilic Substitution in the Triazole N-Oxides and N-Methoxytriazolium Salts: Preparation of Substituted 1,2,3-Triazoles

2-Phenyltriazole 1-oxides are activated at C-5 towards both electrophilic and nucleophilic attack.The N-oxides can be selectively halogenated and, in turn, the halogen replaced by strong nucleophiles.On subsequent deoxygenation, the N-oxides yield halogeno-, methylthio-, and methoxy-triazoles.Methylation produces N-methoxytriazolium salts in which H-5 can be replaced by weak nucleophiles, e.g. fluoride ions.Thus fluoro-, chloro-, hydroxy-, alkoxy-, acyloxy-, amino-, substituted amino-, azido-, nitro-, mercapto-, alkylthio-, acylthio-, and cyano-substituents can be introduced in the triazole nucleus.Alternatively deprotonated N-methoxytriazolium salts react with electrophiles producing substituted triazole N-oxides.The reactions of triazole N-oxides with hydrogen chloride to give chlorotriazoles, and with acetyl chloride to give acetoxytriazoles, are explained.