A Ceric Ammonium Nitrate N-Dearylation of <i>N</i>-<i>p</i>-Anisylazoles Applied to Pyrazole, Triazole, Tetrazole, and Pentazole Rings: Release of Parent Azoles. Generation of Unstable Pentazole, HN<sub>5</sub>/N<sub>5</sub><sup>-</sup>, in Solution
作者:Richard N. Butler、John M. Hanniffy、John C. Stephens、Luke A. Burke
DOI:10.1021/jo702423z
日期:2008.2.1
pentazole ring. The unstable HN5/N5- produced at −40 °C did not build up in the solution but degraded to azide ion and nitrogen gas with a short lifetime. The 15N-labeling of the N3- ion obtained from all samples proved unequivocally that it came from the degradation of HN5 (tautomeric forms) and/or its anion N5- in the solution.
Abstract An efficient and simple oxidative protocol has been developed for the preparation of pyrazoles from pyrazolines mediated by TBHP/Cu(OAc)2 at room temperature. The present protocol has been successfully applied for the preparation of various pyrazole compounds from heterocyclic pyrazolines.
First generation of pentazole (HN5, pentazolic acid), the final azole, and a zinc pentazolate salt in solution: A new N-dearylation of 1-(p-methoxyphenyl) pyrazoles, a 2-(p-methoxyphenyl) tetrazole and application of the methodology to 1-(p-methoxyphenyl) pentazoleElectronic supplementary information (ESI) available: experimental details. See http://www.rsc.org/suppdata/cc/b3/b301491f/
作者:R. N. Butler、John C. Stephens、Luke A. Burke
DOI:10.1039/b301491f
日期:2003.4.3
Ceric ammonium nitrate (CAN) in methanol-water gave a new N-dearylation of a series of substituted 1-(p-methoxyphenyl) pyrazoles and a 2-(p-methoxyphenyl)tetrazole producing p-benzoquinone and the parent azole in a mole for mole ratio. Application of this reaction to 1-(p-methoxyphenyl) pentazole at -40 degrees C produced p-benzoquinone. 15N NMR spectra suggest that pentazole, HN5, was also produced