AMINOALKYLATION OF QUINAZOLINES AND QUINAZOLONES VIA GRIGNARD REACTIONS .5. GRIGNARD REACTIONS WITH HALOALKYLIMINES

Quinazoline is aminoalkylated at C(4) by 3‐dimethylaminopropyl‐magnesium‐chloride in preparative yield to give 3, and by oxidation 5, just as aryl and alkyl‐magnesiumbromide give 15, 19, and 22. These 4‐substituted quinazolines yield by further treatment with the same GRIGNARD compound by 3, 4 or 1, 2‐addition 3, 4‐di‐hydro‐quinazolines (12, 16) and 1, 2‐dihydro‐quinazolines (13, 17, 20, 23), the latter being formed exclusively when the 4‐position in the quinazoline is occupied by bulky residues; only the later can be oxidised to give 2,4‐disubstituted aromates (cf 14, 18, 21, 24). The spectroscopic and physicochemical behaviour of the dihydro compounds and the aromatic and the aromatic compounds are discussed. Copyright © 1969 Verlag GmbH & Co. KGaA, Weinheim