Rapid and eco-friendly high yield synthesis of dihydroquinazolinones mediated by urea/zinc chloride eutectic mixture

Tryptanthrin and Its Derivatives in Drug Discovery: Synthetic Insights

“…Urea/zinc chloride proved to be suitable to synthesize tryptanthrin in excellent yield (91%). 29 Some catalytic protocols have also been recently described as efficient synthetic pathways for the condensation of isatin and isatoic anhydride. The use of a low-cost, non-toxic and recyclable heterogeneous catalyst, such as zinc oxide nanoparticles (ZnO-NPs) enabled the preparation of tryptanthrin (92% yield) and tryptanthrin derivatives based on aryl-substituted isatins (five examples, 82-94% yield) in an efficient manner under mild conditions (room temperature using ethanol as solvent).…”

“…The use of multicomponent reactions (MCRs) is also a suitable strategy for the preparation of new tryptanthrinbased derivatives. Filatov et al explored the 1,3-dipolar cycloaddition of azomethine ylides formed in situ (obtained from the reaction between tryptanthrins (1′) and -amino acids (29) or simple peptides (30)) and cyclopropenes (31). This approach allowed the preparation of 25 spiro derivatives (31, 43-80% yield, and 32, 31-77% yield) in moderate to very good yields (Scheme 12).…”

An eco‐friendly, sustainable, and greener approach to the synthesis of Dihydroquinazolin‐4(1H)‐ones using a deep eutectic solvent

“…The acetone reacted smoothly and gave a good yield (82%) 3y, but it took longer time than aldehydes. The mechanistic pathway for the DES-mediated DHQ has been proposed as per the literature and is outlined in Figure 3 [42][43][44][45][46]. First, the ZnCl 2 present in DES, activated the benzaldehyde 2b and initiated the reaction by forming an H-bond (hydrogen bond) with its carbonyl group.…”

Caffeinium Hydrogen Sulphate Catalysed Green Synthesis of 2,3- Dihydroquinazolin-4(1H)-ones and Their Drug-likeness Studies as Antibacterial Agents

“…Among these, the cyclocondensation of anthranilamide with aryl aldehydes is the most effective and popular method for producing 2,3-dihydroquinazolin-4(1H)-ones. For this purpose various catalysts such as strong Bronsted acids, Lewis acids, metal triflates, ammonium salts [12], IL@MNP [13], tribromide ion supported on boehmite nanoparticles [14], B(C6F5)3 [15], nano-ZrO2-Al2O3 [16], urea/zinc chloride [17], Gr@SO3H [18], Fe3O4@PEG-diaza crown ether@Ni [19], Fe3O4@PEG-Ni [20], ZnO nanomicelle [21], SBA-15@n-Pr-THAM-ZrO [22] and MCM-41-SPM-DMG-Cu(II) [23] have been utilized. Many of these systems have several drawbacks, including poor product yields, long reaction times, difficult reaction conditions, expensive catalysts and hazardous solvents.…”