Microwave enhanced synthesis of 4-aminoquinazolines

Microwave‐Promoted, One‐Pot, Solvent‐Free Synthesis of 4‐Arylcoumarins from 2‐Hydroxybenzophenones

“…Thus, ethyl cyanoacetate and imine 2 were irradiated with microwaves (10 min, 180°C) in the presence of tBuOK (10 mol-%). tBuOK was the base chosen, as it has proven to be particularly useful in MAOS and has been applied successfully to obtain various skeletons (4-aminoquinazolines, [33] indolines, [34] and pyrazole [3,4-d] pyrimidine [35] ). This allowed us to isolate a compound whose characterization confirmed that the condensation had taken place, and as expected, the cyclization occurred spontaneously to form the neoflavonoid skeleton, obtaining compound 8 in 47 % yield (Scheme 2).…”

Synthesis and Biological Evaluation of Some Quinazoline Heterocyclic Derivatives

“…The chemotherapeutic use of quinazoline alkaloids may date back to the ancient Chinese treatment of malaria with the herbal preparations from Dichroa febrifuja [65]. At present, some synthetic quinazoline-based drugs such as metolazone, quinethazone, and prazosin have acquired medicinal approval for their unique pharmacological indices and many others are under clinical evaluation [66][67][68][69][70][71]. In this synthesis, a series of quinazoline derivatives were afforded by adopting anhydrous THF as solvent and the TiCl 4 -Zn system as reducing agent.…”

Heterocyclic Chemistry Using Microwave‐Assisted Approaches

“…A similar rapid microwave one-pot synthesis of substituted quinazolin-4-ones was also reported, which involved cyclocondensation af anthranilic acid, formic acid (or an orthoester) and an amine under solvent-free conditions (Scheme 3.37) 61 . A complimentary approach was adopted to synthesise 4-aminoquinazolines in very good yields, involving the reaction of aromatic nitrile compounds with 2-aminobenzonitrile in the presence of a catalytic amount of base (Scheme 3.38) 62 . The reactions were performed in a domestic microwave oven and required only a very short heating time.…”