Microwave Reaction of Diazonium Salts with Nitriles

Abstract

A series of aryldiazonium tetrafluorborates dissolved in nitriles have been converted into the corresponding anilides in almost quantitative yield in 1 min by microwave irradiation. When bromoacetonitrile was used, 2,4-bis(bromophenyl)-quinazoline was formed. The reaction of malononitrile with the diazonium salt, in DMF as a solvent, afforded 2-(dimethylaminomethylene) malononitrile and phenylhydrazone propanedinitrile.

Synthesis of Substituted Quinazolin-4(3H)-imines From Aryldiazonium Salts, Nitriles and 2-Cyanoanilines via A Metal-Free Tandem Approach

“…In continuation of our recent studies on the use of aryldiazonium salt as the precursor for the preparation of various heterocycles, herein, we report a general, mild, and transition metal-free synthesis of quinazolin-4­(3 H )-imines (Scheme ). We envision that the reactive N -arylnitrilium intermediate ( 2 ), generated in situ from the reaction of the arenediazonium salt with a nitrile molecule, , could further react with o -cyanoanilines via amination/tandem cyclization to afford quinazolin-4­(3 H )-imines directly.…”

Discovery of a New Class of Sortase A Transpeptidase Inhibitors to Tackle Gram-Positive Pathogens: 2-(2-Phenylhydrazinylidene)alkanoic Acids and Related Derivatives

“…The cyano derivative 6a shows a signal in the 1 H-NMR spectrum at δ 9.49 which excludes the H-bond of the NH with the carbonyl group. This view is supported by the 1 H-NMR spectrum of 2-(2-phenylhydrazinylidene)propanodinitrile ( 9 ) [33] (see Figure 2), which shows the NH chemical shift at δ 9.57, a value very near to δ 9.49. Compound 6 might presumably be arranged to a dimeric form of type 10 where each single molecule show the E structure (see Figure 3).…”

Design and Synthesis of Small Molecules as Potent Staphylococcus aureus Sortase A Inhibitors

“…Through a comparison of the 1 H NMR spectroscopic information for the reference molecules, the obtained materials, 31 and 32 , were confirmed to be E and Z, respectively [ 72 , 73 , 74 ]. For the E-configurated molecule, 31 , the hydrogen of NH and the oxygen of the acetyl moiety form intramolecular hydrogen bonding, depicting an apparent downfield shift of NH and methyl signals compared to the Z-geometry [ 75 , 76 ].…”

“…For the E-configurated molecule, 31, the hydrogen of NH and the oxygen of the acetyl moiety form intramolecular hydrogen bonding, depicting an apparent downfield shift of NH and methyl signals compared to the Z-geometry [75,76].…”