Synthesis Of 4-aminoquinazolines Research Articles

Palladium-Catalyzed Synthesis of 4-Aminoquinazolines from Amide Oxime Ethers and 2-Iodobenzonitrile

4-Substituted O-benzyl benzamide oximes reacted with 2-iodobenzonitrile in the presence of 0.1 mol % of [Pd2(dba)3], 0.2 mol % of XantPhos, and 1.5 equiv of Cs2CO3 in dioxane under argon to give 2-arylquinazolin-4-amines. The described reaction is a new type of cascade processes, which affords 4-amino-quinazoline derivatives without using highly reactive chlorinating agents.

Dawson Heteropolyacid: A Green, Eco-Friendly, and Reusable Catalyst for One-Pot Synthesis of 4-Aminoquinazolines

A new multicomponent synthesis of 4-aminoquinazolines from the reaction of anthranilonitrile, acylchlorides, and ammonium acetate in the presence of catalytic amounts of Dawson-type heteropolyacids (HPAs) is reported. The catalytic performance of different forms of Dawson-type HPAs, H6 P2M18O62 (M = WVI, MoVI) and mixed addenda forms (M = CoII, CuII, NiII, MnIII) were compared and in all cases, maximum of yield was observed by using H6P2W18O62 as catalyst. The plausible mechanism was estimated. In all cases, the Dawson catalyst was easily recovered and recycled with retention of their initial structure and activity. The effects of reaction conditions have been studied and the results showed yields of reaction are good to excellent.

One-Pot Synthesis of 4-Aminoquinazolines by Hexamethyldisilazane-Mediated Reaction of Quinazolin-4(3H)-ones with Amines

Hexamethyldisilazane-mediated reaction of quinazolin-4(3H)-ones with primary amines led to facile formation of 4-aminoquinazolines through tandem silylation and substitution in a single pot. Excellent yields of the products (83–97%) and environmental friendliness (avoiding the use of chlorination reagents) are the advantages of this method.