ChemInform Abstract: Halochromic Molecules. Part 7. Synthesis and Acidobasic Properties of Substituted Heteroarenoquinazolines.

Abstract

On treatment with acid the title compounds (IIIb)‐(IIId) form ring‐opened, blue triphenylcarbenium salts of the Rhoduline‐R type, while (IIIa) remains colorless.

One-Pot Tandem Assembly of Amides, Amines, and Ketones: Synthesis of C4-Quaternary 3,4- and 1,4-Dihydroquinazolines

“…Alternatively, quaternary 3,4-DHQs have been constructed from the corresponding tertiary counterparts through alkylation of select acidic substrates following deprotonation with NaH . Other examples of quaternary 3,4-DHQ synthesis include addition of nitriles to functionalized hydroxymethylanilines in the presence of acids, intramolecular attack of amidines onto tethered alkenes, and Ugi multicomponent assembly, among others . A recent focus of quaternary DHQ synthesis has been for the construction of natural products hinckdentine A and trigonoliimines A and B .…”