80957-43-3Relevant 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
Begtrup, Mikael
, p. 717 - 728 (2007/10/03)
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.
Activation of Exocyclic α-Positions of Azole N-Oxides by O-Silylation
Begtrup, Mikael,Vedso, Per
, p. 2555 - 2564 (2007/10/02)
Exocyclic α-positions at immonium ring carbon atoms of pyrazole and 1,2,3-triazole 1-oxides are selectively attacked in a one-pot sequence comprising silylation with iodotrimethylsilane, deprotonation with 1,2,2,6,6-pentamethylpiperidine and allylic substitution of the trimethylsilyloxy group with the iodide ions liberated by the silylation.In this way 3- and 5-iodomethylpyrazoles as well as 4-iodomethyl-1,2,3-triazoles are obtained in good yields.These may be useful for the preparation of heteroarylmethyl derivatives since the iodine atom can be displaced by even weak nucleophiles such as acetate ions.The side chain iodination is complementary to O-alkylation of the N-oxides followed by nucleophilic attack which preferentially takes place at ring carbon atoms.
