Synthesis of dihydroquinazolines from 2-aminobenzylamine: N³-aryl derivatives with electron-withdrawing groups

• Nadia Gruber,
• Jimena E. Díaz and
• Liliana R. Orelli

Beilstein J. Org. Chem. 2018, 14, 2510–2519, doi:10.3762/bjoc.14.227

• reaction promoted by trimethylsilyl polyphosphate (PPSE) is also proposed on the basis of literature data and our experimental observations. Keywords: cyclodehydrations; dihydroquinazolines; microwaves; nitrilium ions; PPSE; SNAr; Introduction Dihydroquinazolines (DHQs) represent heterocyclic cores of

• alternative mechanism involving nitrilium ions as intermediates can be proposed (Scheme 4). Nitrilium ions [91] are known to mediate different organic reactions such as the Beckmann rearrangement and the Bischler–Napieralski, von Braun and Ritter reactions, among others [92][93]. Stable nitrilium salts can be

• generated by Lewis acid-promoted halide abstraction from imidoyl chlorides or by alkylation of nitriles. A nucleophilic attack on such species followed by cyclization provides access to a variety of heterocycles. Intramolecular reactions of in situ generated nitrilium ions leading to heterocyclic compounds