Convenient and Practical One-Pot Synthesis of 4-Chloropyrimidines via a Novel Chloroimidate Annulation

A microwave assisted tandem synthesis of quinazolinones using ionic liquid supported copper(II) catalyst with mechanistic insights

Quinazolinone is a preferred structural motif with notable pharmacological activity that is present in a wide range of naturally occurring compounds. A microwave assisted tandem cyclooxidative method has been developed to afford quinazolinones via a recyclable ionic liquid supported copper catalyst. This sustainable method exhibits operational simplicity through a rapid, clean, and energy-efficient route and a variety of 2-substituted quinazolinones are obtained in excellent yields. In addition, this innovative approach enables us to develop a library of nitriles in an environment-friendly synthetic protocol. Moreover, the catalyst can be recycled and reused up to three consecutive cycles without any significant loss of catalytic activity. Further organic transformation of the synthesized quinazolinones was carried out to afford reported as well as novel bioactive heterocyclic compounds.

Design and Optimization of Quinazoline Derivatives: New Non-nucleoside Inhibitors of Bovine Viral Diarrhea Virus

Bovine viral diarrhea virus (BVDV) belongs to the Pestivirus genus (Flaviviridae). In spite of the availability of vaccines, the virus is still causing substantial financial losses to the livestock industry. In this context, the use of antiviral agents could be an alternative strategy to control and reduce viral infections. The viral RNA-dependent RNA polymerase (RdRp) is essential for the replication of the viral genome and constitutes an attractive target for the identification of antiviral compounds. In a previous work, we have identified potential molecules that dock into an allosteric binding pocket of BVDV RdRp via a structure-based virtual screening approach. One of them, N-(2-morpholinoethyl)-2-phenylquinazolin-4-amine [1, 50% effective concentration (EC₅₀) = 9.7 ± 0.5 μM], was selected to perform different chemical modifications. Among 24 derivatives synthesized, eight of them showed considerable antiviral activity. Molecular modeling of the most active compounds showed that they bind to a pocket located in the fingers and thumb domains in BVDV RdRp, which is different from that identified for other non-nucleoside inhibitors (NNIs) such as thiosemicarbazone (TSC). We selected compound 2-[4-(2-phenylquinazolin-4-yl)piperazin-1-yl]ethanol (1.9; EC₅₀ = 1.7 ± 0.4 μM) for further analysis. Compound 1.9 was found to inhibit the in vitro replication of TSC-resistant BVDV variants, which carry the N264D mutation in the RdRp. In addition, 1.9 presented adequate solubility in different media and a high-stability profile in murine and bovine plasma.

Conversion of Quinazoline Modulators from Inhibitors to Activators of β-Glucocerebrosidase

Gaucher's disease is a lysosomal disease caused by mutations in the β-glucocerebrosidase gene ( GBA1 and GCase) that have been also linked to increased risk of Parkinson's disease (PD) and Diffuse Lewy body dementia. Prior studies have suggested that mutant GCase protein undergoes misfolding and degradation, and therefore, stabilization of the mutant protein represents an important therapeutic strategy in synucleinopathies. In this work, we present a structure-activity relationship (SAR) study of quinazoline compounds that serve as inhibitors of GCase. Unexpectedly, we found that N-methylation of these inhibitors transformed them into GCase activators. A systematic SAR study further revealed that replacement of the key oxygen atom in the linker of the quinazoline derivative also contributed to the activity switch. PD patient-derived fibroblasts and dopaminergic midbrain neurons were treated with a selected compound (9q) that partially stabilized GCase and improved its activity. These results highlight a novel strategy for therapeutic development of noninhibitory GCase modulators in PD and related synucleinopathies.

Design and Synthesis of Potent Quinazolines as Selective β-Glucocerebrosidase Modulators

Gaucher's disease is a common genetic disease caused by mutations in the β-glucocerebrosidase (GBA1) gene that have been also linked to increased risk of Parkinson's disease and Lewy body dementia. Stabilization of misfolded mutant β-glucocerebrosidase (GCase) represents an important therapeutic strategy in synucleinopathies. Here we report a novel class of GCase quinazoline inhibitors, obtained in a high throughput screening, with moderate potency against wild-type GCase. Rational design and a SAR study of this class of compounds led to a new series of quinazoline derivatives with single-digit nanomolar potency. These compounds were shown to selectively stabilize GCase when compared to other lysosomal enzymes and to increase N370S mutant GCase protein concentration and activity in cell assays. To the best of our knowledge, these molecules are the most potent noniminosugar GCase modulators to date that may prove useful for future mechanistic studies and therapeutic approaches in Gaucher's and Parkinson's diseases.

Molecular and supramolecular chemistry of rosette nanotubes

Synthetic strategies used to tune the properties of a class of supramolecular 1D nanostructures, the rosette nanotubes, are reviewed herein.