A study concerning the synthesis,basicity and hydrolysis of 4‐amino‐2‐(N,N‐diethylamino)quinazoline derivatives

A group of 2‐(N,N‐diethylamino)‐4‐aminoquinazoline derivatives have been synthesized in the reaction of N¹,N¹‐diethyl‐N²‐arylchlorocarboxyamidines with cyanamide in the presence of T1Cl₄ as a catalyst. Such quinazolines decompose into the corresponding quinazolones in dilute aqueous HC1 solutions at higher temperature. Hydrolysis rates of 2‐(N,N‐diethylamino)‐4‐aminoquinazoline and 2‐(N,N‐diethylamino)‐4‐(N,N‐dimethylamino)‐quinazoline have been determined to observe the influence of substituents at the 4‐amino group upon the hydrolysis. pK_a values have been also determined for these compounds and analyzed in conjunction with the Hammett σ constants.