An Efficient Procedure for the Synthesis of Crystalline Aryldiazonium Trifluoroacetates – Synthetic Applications

Abstract

We have developed a very mild procedure for the synthesis of crystalline aryldiazonium trifluoroacetate salts in high yields under anhydrous conditions. Over thirty mono‐ or polyfunctional aniline derivatives have been diazotized by this method, including water‐ and acid‐sensitive substrates. The o‐ and p‐hydroxyaryldiazonium salts, derived from the corresponding anilines, could be deprotonated by treatment with K2CO3 to yield pure diazoquinones. NMR and UV/Vis spectra have been recorded for all the synthesized salts; the data are in good agreement with the rather limited published data and constitute a first extensive report of 13C‐NMR chemical shifts in diazonium salts. An excellent linear relationship emerged between Brown's substituent constants s+p and the 13Cipso chemical shifts. The diazonium salts obtained proved to be much more soluble in organic solvents than their tetrafluoroborate counterparts. They were tested in Pd‐mediated coupling reactions of various Carbon‐Carbon double bonds, and were found to give good yields within short reaction times under very mild conditions. We believe that diazonium trifluoroacetates represent a very attractive alternative to diazonium tetrafluoroborates.

Evaluation and Biological Properties of Reactive Ligands for the Mapping of the Glycine Site on theN-Methyl-d-aspartate (NMDA) Receptor

“…The diazonium 13d was obtained according to a protocol recently developed in our laboratory. 24 Acylation of the 4-hydroxy group in L-701.324 with p-(fluorosulfonyl)benzoyl chloride in CH 2 Cl 2 gave the target compound 13e. Ligands 15a-c bearing a single phenyl ring in position 3 of the quinolinone were prepared following the described synthesis of L-701.324 except that 3-nitrophenylacetic acid was used instead of 3-phenoxyphenylacetic acid.…”

Arenediazonium o-Benzenedisulfonimides: Some Kinetics of Azo Coupling Reactions with Naphthols

“…The obtaining of arenediazonium tetrafluoroborates, which may be stored and are commercially available in some cases, produced an improvement in such quantitative investigations. Recently, the synthesis of other stable arenediazonium salts, such as arenediazonium o-benzenedisulfonimides [2] and trifluoroacetates [3] has been reported. In particular, the simple method used for the preparation and isolation of dry arenediazonium o-benzenedisulfonimides has recently allowed the production of quite a large number of arenediazonium ions with exceptional stability and high grades of purity, and these salts have been successfully used in a number of synthetic reactions.…”

History of the AFRL/USC DARPA Program on Polynitrogen Chemistry. Volume 2

“…Its barrier towards decomposition to N 3 -+ N 2 is predicted to be 28 kcal/mol (see The arylpentazoles and the corresponding diazonium salt precursors were prepared and characterized at AFRL using literature methods [Ref. 35, 36, 38, 39,45,50] and multinuclear NMR spectroscopy . The ESI-MS cleavage experiments were carried out by Dr.…”

“…49 The barrier 6 to form N7 + N3 from N5 + /N5 -is very similar to the endothermicity of the reaction, and this process again involves two open shell molecules. A closed shell asymptote of geometry similar to that of the end-on addition of N5 + to N5 -is N8 + N2, which is 230 kcal/mol above 5N2 at the CCSD(T)/6-311G*//MP2/6-31G* level 50 and, thus, substantially downhill from the ion pair by ∼67 kcal/mol. The N8 molecule that is formed, azidopentazole, has a barrier to formation of 4 N2 of only 13-14 kcal/mol at the CCSD(T)/6-311G* level 49 …”