68375-95-1Relevant academic research and scientific papers
Cycloaddition of Sodium Azide to polarized Ketene S,S- and S,N-Acetals: Synthesis of Novel Substituted Triazole and Tetrazole Derivatives
Chakrasali, R. T.,Ila, H.,Junjappa, H.
, p. 453 - 455 (2007/10/02)
Thermal cycloaddition of aroylketene dithioacetals 1a-e with sodium azide affords novel 4-aroyl-5-methylthio-1H-1,2,3-triazoles 3a-e.The corresponding S,N-acetals 5a-m derived from primary amines react with sodium azide through different pathway inv
Imidoyl Azide to Tetrazole Cyclization Limited by Internal Hydrogen Bonding and Imine Isomerization
Hegarty, Anthony F.,Ahern, Edward P.
, p. 1342 - 1346 (2007/10/02)
The rates of cyclization of the 2-azido-3-benzoyl enamine 6 to the corresponding tetrazole 9 have been measured in D2O as a function of pD at 25 deg C.A complex pD-rate profile is observed with a maximum rate at a pD of ca. 2.0.The observed rate constants are reduced (typically 7-fold) in D2O in those regions where proton transfer to the enamine is rate determining; however, the actual rate of isomerization about the iminium ion intermediate (C=N+) remains unchanged in D2O, indicating that the solvent most likely does not add reversibly in the slow step for isomerization.The imidoyl azide 15 is stabilized in the open-chain azido form by internal hydrogen bonding to the o-OH group.Both the neutral (15) and anionic (16) forms cyclize to the tetrazole 18, the latter 35-fold more rapidly.The protonated species 17 does not cyclize to the tetrazole and is inert to hydrolysis.
Mechanism of Cyclization of 2-Azido-3-benzoyl Enamines to 5-Phenacyltetrazoles: Rate-Limiting Proton Transfer and Iminium Ion Isomerization
Ahern, Edward P.,Dignam, Kieran J.,Hegarty, A.F.
, p. 4302 - 4308 (2007/10/02)
The unusual stability of the azides 5 has been investigated; these are shown to exist as the enamine tautomer 5b. The rates of cyclization of the azides 5b and 14 to the corresponding tetrazoles 4b and 4c (in water at 25 deg C) vary in a complex way with
