Nano-indium oxide: An efficient catalyst for one-pot synthesis of 2,3-dihydroquinazolin-4(1H)-ones with a greener prospect

2,3-Dihydroquinazolin-4(1H)-ones and quinazolin-4(3H)-ones as broad-spectrum cytotoxic agents and their impact on tubulin polymerisation

Tubulin plays a central role in mitosis and has been the target of multiple anticancer drugs, including paclitaxel. Herein two separate families of 2,3-dihydroquinazoline-4(1H)-ones and quinazoline-4(3H) ones, comprising 57 compounds in total, were synthesised. Screening against a broad panel of human cancer cell lines (HT29 colon, U87 and SJ-G2 glioblastoma, MCF-7 breast, A2780 ovarian, H460 lung, A431 skin, Du145 prostate, BE2-C neuroblastoma, and MIA pancreas) reveals these analogues to be broad spectrum cytotoxic compounds. Of particular note, 2-styrylquinazolin-4(3H)-one 51, 2-(4-hydroxystyryl)quinazolin-4(3H)-one 63, 2-(2-methoxystyryl)quinazolin-4(3H)-one 64 and 2-(3-methoxystyryl)quinazolin-4(3H)-one 65 and 2-(naphthalen-1-yl)-2,3-dihydroquinazolin-4(1H)-one 39 exhibited sub-μM potency growth inhibition values. Of these 1-naphthyl 39 has activity <50 nM against the HT29, U87, A2780, H460 and BE2-C cell lines. Molecular modelling of these compounds, e.g. 2-(naphthalen-1-yl)-2,3-dihydroquinazolin-4(1H)-one 39, 2-(2-methoxystyryl)quinazolin-4(3H)-one 64, 2-(3-methoxystyryl)quinazolin-4(3H)-one 65, and 2-(4-methoxystyryl)quinazolin-4(3H)-one 50 docked to the known tubulin polymerisation inhibitor sites highlighted well conserved interactions within the colchicine binding pocket. These compounds were examined in a tubulin polymerisation assay alongside the known tubulin polymerisation promotor, paclitaxel (69), and tubulin inhibitor, nocodazole (68). Of the analogues examined, indoles 43 and 47 were modest promotors of tubulin polymerisation, but less effective than paclitaxel. Analogues 39, 64, and 65 showed reduced microtubule formation consistent with tubulin inhibition. The variation in ring methoxy substituent with 50, 64 and 65, from o- to m- to p-, results in a concomitant reduction in cytotoxicity and a reduction in tubulin polymerisation, with p-OCH350 being the least active in this series of analogues. This presents 64 as a tubulin polymerisation inhibitor possessing novel chemotype and sub micromolar cytotoxicity. Naphthyl 39, with complete inhibition of tubulin polymerisation, gave rise to a sub 0.2 μM cell line cytotoxicity. Compounds 39 and 64 induced G2 + M cell cycle arrest indicative of inhibition of tubulin polymerisation, with 39 inducing an equivalent effect on cell cycle arrest as nocodazole (68).

Dihydroquinazolin-4(1H)-one derivatives as novel and potential leads for diabetic management

A variety of dihydroquinazolin-4(1H)-one derivatives (1-37) were synthesized via "one-pot" three-component reaction scheme by treating aniline and different aromatic aldehydes with isatoic anhydride in the presence of acetic acid. Chemical structures of compounds were deduced by different spectroscopic techniques including EI-MS, HREI-MS, ¹H-, and ¹³C-NMR. Compounds were subjected to α-amylase and α-glucosidase inhibitory activities. A number of derivatives exhibited significant to moderate inhibition potential against α-amylase (IC₅₀ = 23.33 ± 0.02-88.65 ± 0.23 μM) and α-glucosidase (IC₅₀ = 25.01 ± 0.12-89.99 ± 0.09 μM) enzymes, respectively. Results were compared with the standard acarbose (IC₅₀ = 17.08 ± 0.07 μM for α-amylase and IC₅₀ = 17.67 ± 0.09 μM for α-glucosidase). Structure-activity relationship (SAR) was rationalized by analyzing the substituents effects on inhibitory potential. Kinetic studies were implemented to find the mode of inhibition by compounds which revealed competitive inhibition for α-amylase and non-competitive inhibition for α-glucosidase. However, in silico study identified several important binding interactions of ligands (synthetic analogues) with the active site of both enzymes.

β-Cyclodextrin: a supramolecular catalyst for metal-free approach towards the synthesis of 2-amino-4,6-diphenylnicotinonitriles and 2,3-dihydroquinazolin-4(1H)-one

β-Cyclodextrin, a green and widespread supramolecular catalyst, has been explored as a highly proficient promoter for the metal-free one-pot multi-component synthesis of a vast range of highly functionalized bioactive heterocyclic moiety, 2-amino-4,6-diphenylnicotinonitriles and 2,3-dihydroquinazolin-4(1H)-one, from easily available precursor aldehydes. The main endeavor of these protocols is to explore this organic supramolecule in one-pot multi-component synthesis. Absence of metal catalyst or toxic acid and harsh reaction conditions, excellent functional group tolerance, inexpensive, greener and environmentally safe protocol are the key advantages of this work.

One-pot synthesis of benzopyrano[2,3-d]pyrimidine derivatives catalyzed by LDHs@Propyl-ANDSA

A general, effective, and operationally simple approach to highly substituted benzopyrano[2,3-d]pyrimidine through the annulation of salicylaldehydes, malononitrile, and secondary amines is explained. The reaction is promoted by the Brønsted–Lowry acid, furnishing a variety of benzopyrano[2,3-d]pyrimidine derivatives in synthetically useful yields.

A Facile Microwave and SnCl2 Synthesis of 2,3-Dihydroquinazolin-4(1H)-ones

An elegantly simple, facile, and robust approach to a scaffold of biological importance, 2,3-dihydroquinazolin-4(1H)-ones, is reported. A catalytic 1% SnCl2/microwave-mediated approach afforded access to pure material, collected by cooling and filtration after 20-min microwave irradiation at 120°C. A total of 41 analogues were prepared in isolated yields of 17–99%. This process was highly tolerant of aliphatic, aromatic, heterocyclic, and acyclic aldehydes, but furan, pyrrole, and thiophene aldehyde reactivity correlated with propensity towards electrophilic addition and/or Diels–Alder addition. As a result, thiophene afforded high yields (80%) whereas pyrrole carboxaldehyde failed to react. With simple cinnamaldehydes, and in the SbCl3-mediated reaction, and with α,β-unsaturated aldehydes the equivalent quinazolin-4(3H)-ones, and not the 2,3-dihydroquinazolin-4(1H)-ones, was favoured.

Co-aminobenzamid@Al-SBA-15: a favorable catalyst in synthesis of 2,3-dihydroquinazolin-4(1H)-ones

The novel hybrid Co-aminobenzamid@Al-SBA-15 was synthesized as a modified mesoporous catalyst. To achieve this aim, the obtained materials were investigated by various techniques including Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), N2 adsorption-desorption, field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) to examine the functional groups, crystallinity, surface area, morphology, particle size distribution and amounts of functional groups, respectively. Co-aminobenzamid@Al-SBA-15 exhibits excellent catalytic activity for the synthesis of 2,3-dihydroquinazolin-4(1H)-ones under mild reaction conditions. The heterogeneous catalyst showed good recyclability and can be reused for ten consecutive cycles without significant loss of its catalytic activity.

2,3-Dihydroquinazolin-4(1H)-one as a privileged scaffold in drug design

2,3-Dihydroquinazolin-4-one (DHQ) belongs to the class of nitrogen-containing heterocyclic compounds representing a core structural component in various biologically active compounds. In the past decades, several methodologies have been developed for the synthesis of the DHQ framework, especially the 2-substituted derivatives. Unfortunately, multistep syntheses, harsh reaction conditions, and the use of toxic reagents and solvents have limited their full potential as a versatile fragment. Recently, use of green chemistry and alternative strategies are being explored to prepare diverse DHQ derivatives. This fragment is used as a synthon for the preparation of biologically active quinazolinones and as a functional substrate for the synthesis of modified DHQ derivatives exhibiting different biological properties. In this review, we provide a comprehensive assessment of the synthesis and biological evaluations of DHQ derivatives.

Crosslinked chitosan nanoparticle-anchored magnetic multi-wall carbon nanotubes: a bio-nanoreactor with extremely high activity toward click-multi-component reactions

In the present study, we have designed a procedure for the synthesis of a bio-nanoreactor catalyst, crosslinked chitosan nanoparticle-anchored magnetic multi-wall carbon nanotubes (CS NPs/MWCNT@Fe₃O₄), via an in situ ionotropic gelation method.

One-pot synthesis and antifungal activity against plant pathogens of quinazolinone derivatives containing an amide moiety

An efficient one-pot, three-component synthesis of quinazolinone derivatives containing 3-acrylamino motif was carried out using CeO2 nanoparticles as catalyst. Thirty-nine synthesized compounds were obtained with satisfied yield and elucidated by spectroscopic analysis. Four phytopathogenic fungi were chosen to test the antifungal activities by minimum inhibitory concentration (MIC) method. Compounds 4ag, 4bb, 4bc showed broad antifungal activities against at least three fungi, and dramatic effects of substituents on the activities were observed. Docking studies were established to explore the potential antifungal mechanism of quinazolinone derivatives as the chitinase inhibitors, and also verified the importance of the amide moiety.

Access to enhanced catalytic core–shell CuO–Pd nanoparticles for the organic transformations

This paper describes the biosynthesis of core–shell CuO–Pd nanocatalysts with the aid of a Cyperus rotundus rhizome extract.

Hydroxyapatite nanoparticles (HAP NPs): a green and efficient heterogeneous catalyst for three-component one-pot synthesis of 2,3-dihydroquinazolin-4(1H)-one derivatives in aqueous media

HAP NPs were applied as a green heterogeneous catalyst for synthesis of 2,3-dihydroquinazolin-4(1H)-one derivatives. The nanocatalyst was prepared and characterized.

Organocatalysis by p-sulfonic acid calix[4]arene: a convenient and efficient route to 2,3-dihydroquinazolin-4(1H)-ones in water

An efficient and eco-friendly method is reported for the synthesis of 2,3-dihydroquinazolin-4(1H)-ones using p-sulfonic acid calix[4]arene as a recyclable organocatalyst in excellent yields in water at room temperature.

A novel, facile, rapid, solvent free protocol for the one pot green synthesis of chromeno[2,3-d]pyrimidines using reusable nano ZnAl2O4– a NOSE approach and photophysical studies

The preparation of an eco-friendly, highly stable, reusable nano ZnAl₂O₄was used as an excellent catalyst for the pseudo four component synthesis of a library of fluorescent chromeno[2,3-d]pyrimidine derivatives.

Ligand-free reusable nano copper oxide-catalyzed synthesis of 3-amino-1,4-diynes

The synthesis of 3-amino-1,4-diynes has been developed by the two-component coupling of N,N-dimethyl formamide dimethyl acetal with terminal alkynes using CuO nanoparticles as an efficient catalyst under mild reaction conditions.

An ionic liquid catalyzed reusable protocol for one-pot synthesis of 2,3-dihydroquinazolin-4(1H)-one under mild conditions

This article describes an efficient protocol for the syntheses of 2,3-dihydroquinazolinones. The synthetic utility of this methodology has been demonstrated with 30 different substrates. The reaction showed good functional group tolerance and high levels of catalytic activity.

Synthetic approaches, functionalization and therapeutic potential of quinazoline and quinazolinone skeletons: the advances continue

The presence of N-heterocycles as an essential structural motif in a variety of biologically active substances has stimulated the development of new strategies and technologies for their synthesis. Among the various N-heterocyclic scaffolds, quinazolines and quinazolinones form a privileged class of compounds with their diverse spectrum of therapeutic potential. The easy generation of complex molecular diversity through broadly applicable, cost-effective, practical and sustainable synthetic methods in a straightforward fashion along with the importance of these motifs in medicinal chemistry, received significant attention from researchers engaged in drug design and heterocyclic methodology development. In this perspective, the current review article is an effort to recapitulate recent developments in the eco-friendly and green procedures for the construction of highly challenging and potentially bioactive quinazoline and quinazolinone compounds in order to help medicinal chemists in designing and synthesizing novel and potent compounds for the treatment of different disorders. The key mechanistic insights for the synthesis of these heterocycles along with potential applications and manipulations of the products have also been conferred. This article also aims to highlight the promising future directions for the easy access to these frameworks in addition to the identification of more potent and specific products for numerous biological targets.