A Facile Total Synthesis for Large-Scale Production of Imatinib Base

1-Iodoglycal: A Versatile Intermediate for the Synthesis of d-Glyco Amides and Esters Employing Carbonylative Cross-Coupling Reaction

In this study, we present the development of two catalytic processes: a Pd-PEPPSI-catalyzed aminocarbonylation and a Pd(OAc)2-Xantphos-catalyzed alkoxycarbonylation of d-glycals, utilizing carbonylative cross-coupling reactions. We explored successfully various types of aromatic amines, as well as alkyl amines and amino acids, to synthesize new d-glycal amides. However, we observed limitations in the reactivity of alkyl and heteroaromatic amines. The processes enabled the synthesis of 20 novel C1-branched glycoamides and 7 new d-gluco esters.

Harmonizing the craft of crafting clinically endorsed small-molecule BCR-ABL tyrosine kinase inhibitors for the treatment of hematological malignancies

The advancement and practical use of small-molecule tyrosine kinase inhibitors (TKIs) that specifically target the BCR-ABL fusion protein have introduced a revolutionary era of precision medicine for the treatment of chronic myeloid leukemia (CML) and Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL). This review offers a comprehensive exploration of the synthesis, mechanisms of action, and clinical implementation of clinically validated TKIs in the context of BCR-ABL, emphasizing the remarkable strides made in achieving therapeutic precision. We delve into the intricate design and synthesis of these small molecules, highlighting the synthetic strategies and modifications that have led to increased selectivity, enhanced binding affinities, and reduced off-target effects. Additionally, we discuss the structural biology of BCR-ABL inhibition and how it informs drug design. The success of these compounds in inhibiting aberrant kinase activity is a testament to the meticulous refinement of the synthetic process. Furthermore, this review provides a detailed analysis of the clinical applications of these TKIs, covering not only their efficacy in achieving deep molecular responses but also their impact on patient outcomes, safety profiles, and resistance mechanisms. We explore ongoing research efforts to overcome resistance and enhance the therapeutic potential of these agents. In conclusion, the synthesis and utilization of clinically validated small-molecule TKIs targeting BCR-ABL exemplify the transformative power of precision medicine in the treatment of hematological malignancies. This review highlights the evolving landscape of BCR-ABL inhibition and underscores the continuous commitment to refining and expanding the therapeutic repertoire for these devastating diseases.

Unlocking the synthetic approaches and clinical application of approved small-molecule drugs for gastrointestinal cancer treatment: A comprehensive exploration

Gastrointestinal (GI) cancers encompass a group of malignancies affecting the digestive system, including the stomach, esophagus, liver, colon, rectum and pancreas. These cancers represent a significant global health burden, necessitating effective treatment strategies. Small-molecule drugs have emerged as crucial therapeutic options in the fight against GI cancers due to their oral bioavailability, targeted mechanisms of action, and well-established safety profiles. The review then elucidates the clinical applications and synthetic methods of clinically approved small-molecule drugs for the treatment of GI cancer, shedding light on their mechanisms of action and their potential in mitigating GI cancer progression. The review also discusses future prospects and the evolving landscape of small-molecule drug development in GI oncology, highlighting the potential for personalized medicine. In summary, this review provides valuable insights into cutting-edge strategies for harnessing clinically approved small-molecule drugs to combat GI cancer effectively.

Synthesis and application of small molecules approved for the treatment of lymphoma

Lymphoma is a form of cancer that impacts the lymphatic system, which plays a crucial role in defending the body against infections and illnesses. It is characterized by the atypical proliferation of lymphocytes, a type of white blood cell, which can form tumors in the lymph nodes, bone marrow, spleen, etc. Lymphoma is usually treated using a combination of targeted therapy, chemotherapy, and radiation therapy. In recent years, there has been a growing interest in the development of new drugs to treat lymphoma, which has led to the discovery of several promising compounds. The primary targets for lymphoma treatment have been identified as Bruton's tyrosine kinase (BTK), phosphoinositide3-kinase (PI3K), histone deacetylase (HDAC), and DNA polymerase (POLA). This review aims to provide an overview of the clinical applications and synthesis of several notable drugs approved to treat lymphoma, to expedite the exploration of more potent novel medications for the management of lymphoma.

Recent advance of clinically approved small-molecule drugs for the treatment of myeloid leukemia

Myeloid leukemia denotes a hematologic malignancy characterized by aberrant proliferation and impaired differentiation of blood progenitor cells within the bone marrow. Despite the availability of several treatment options, the clinical outlook for individuals afflicted with myeloid leukemia continues to be unfavorable, making it a challenging disease to manage. Over the past, substantial endeavors have been dedicated to the identification of novel targets and the advancement of enhanced therapeutic modalities to ameliorate the management of this disease, resulting in the discovery of many clinically approved small-molecule drugs for myeloid leukemia, including histone deacetylase inhibitors, hypomethylating agents, and tyrosine kinase inhibitors. This comprehensive review succinctly presents an up-to-date assessment of the application and synthetic routes of clinically sanctioned small-molecule drugs employed in the treatment of myeloid leukemia. Additionally, it provides a concise exploration of the pertinent challenges and prospects encompassing drug resistance and toxicity. Overall, this review effectively underscores the considerable promise exhibited by clinically endorsed small-molecule drugs in the therapeutic realm of myeloid leukemia, while concurrently shedding light on the prospective avenues that may shape the future landscape of drug development within this domain.

Rational Design of Highly Potent and Selective Covalent MAP2K7 Inhibitors

The mitogen-activated protein kinase signaling cascade is conserved across eukaryotes, where it plays a critical role in the regulation of activities including proliferation, differentiation, and stress responses. This pathway propagates external stimuli through a series of phosphorylation events, which allows external signals to influence metabolic and transcriptional activities. Within the cascade, MEK, or MAP2K, enzymes occupy a molecular crossroads immediately upstream to significant signal divergence and cross-talk. One such kinase, MAP2K7, also known as MEK7 and MKK7, is a protein of great interest in the molecular pathophysiology underlying pediatric T cell acute lymphoblastic leukemia (T-ALL). Herein, we describe the rational design, synthesis, evaluation, and optimization of a novel class of irreversible MAP2K7 inhibitors. With a streamlined one-pot synthesis, favorable in vitro potency and selectivity, and promising cellular activity, this novel class of compounds wields promise as a powerful tool in the study of pediatric T-ALL.

N-Heterocyclic carbene (NHC)-catalyzed oxidation of unactivated aldimines to amides via imine umpolung under aerobic conditions

Herein, we disclose an NHC-catalyzed aerobic oxidation of unactivated aldimines for the synthesis of amides via umpolung of imines proceeding through an aza-Breslow intermediate. We have developed an eco-friendly method for the conversion of imines to amides by using molecular oxygen in air as the sole oxidant and dimethyl carbonate (DMC) as a green solvent under mild reaction conditions. Broad substrate scope, high yields and gram scale syntheses expand the practicality of the developed method.

A general NHC-catalyzed conversion of imines to amides proceeding through umpolung–oxidation under aerobic conditions in green solvent is reported.

Green Chemistry in the Synthesis of Pharmaceuticals

The principles of green chemistry (GC) can be comprehensively implemented in green synthesis of pharmaceuticals by choosing no solvents or green solvents (preferably water), alternative reaction media, and consideration of one-pot synthesis, multicomponent reactions (MCRs), continuous processing, and process intensification approaches for atom economy and final waste reduction. The GC's execution in green synthesis can be performed using a holistic design of the active pharmaceutical ingredient's (API) life cycle, minimizing hazards and pollution, and capitalizing the resource efficiency in the synthesis technique. Thus, the presented review accounts for the comprehensive exploration of GC's principles and metrics, an appropriate implication of those ideas in each step of the reaction schemes, from raw material to an intermediate to the final product's synthesis, and the final execution of the synthesis into scalable industry-based production. For real-life examples, we have discussed the synthesis of a series of established generic pharmaceuticals, starting with the raw materials, and the intermediates of the corresponding pharmaceuticals. Researchers and industries have thoughtfully instigated a green synthesis process to control the atom economy and waste reduction to protect the environment. We have extensively discussed significant reactions relevant for green synthesis, one-pot cascade synthesis, MCRs, continuous processing, and process intensification, which may contribute to the future of green and sustainable synthesis of APIs.

pH-Mediated Selective Synthesis of N-Allylic Alkylation or N-Alkylation Amines with Allylic Alcohols via an Iridium Catalyst in Water

Amination of allylic alcohols is an effective approach in the facile synthesis of N-allylic alkylation or N-alkylation amines. Recently, a series of catalysts were devised to push forward this transformation. However, current synthetic methods are typically limited to achieve either N-allylic alkylation or N-alkylation products via a certain catalyst. In this article, a pH-mediated selective synthesis of N-allylic alkylation or N-alkylation amines with allylic alcohols via an iridium catalyst with water as the environmental benign solvent is revealed, enabling the miscellaneous synthesis of N-allylic alkylation and N-alkylation products in outstanding yields. Furthermore, a gram-scale experiment with low catalyst loading offers the potential to access a distinct entry for the synthesis of the antifungal drug naftifine.

Selective and Additive-Free Hydrogenation of Nitroarenes Mediated by a DMSO-Tagged Molecular Cobalt Corrole Catalyst

We report on the first cobalt corrole that effectively mediates the homogeneous hydrogenation of structurally diverse nitroarenes to afford the corresponding amines. The given catalyst is easily assembled prior to use from 4-tert-butylbenzaldehyde and pyrrole followed by metalation of the resulting corrole macrocycle with cobalt(II) acetate. The thus-prepared complex is self-contained in that the hydrogenation protocol is free from the requirement for adding any auxiliary reagent to elicit the catalytic activity of the applied metal complex. Moreover, a containment system is not required for the assembly of the hydrogenation reaction set-up as both the autoclave and the reaction vessels are readily charged under a regular laboratory atmosphere.

Drug repurposing for the treatment of COVID-19: Pharmacological aspects and synthetic approaches

In December 2019, a new variant of SARS-CoV emerged, the so-called acute severe respiratory syndrome coronavirus 2 (SARS-CoV-2). This virus causes the new coronavirus disease (COVID-19) and has been plaguing the world owing to its unprecedented spread efficiency, which has resulted in a huge death toll. In this sense, the repositioning of approved drugs is the fastest way to an effective response to a pandemic outbreak of this scale. Considering these facts, in this review we provide a comprehensive and critical discussion on the chemical aspects surrounding the drugs currently being studied as candidates for COVID-19 therapy. We intend to provide the general chemical community with an overview on the synthetic/biosynthetic pathways related to such molecules, as well as their mechanisms of action against the evaluated viruses and some insights on the pharmacological interactions involved in each case. Overall, the review aims to present the chemical aspects of the main bioactive molecules being considered to be repositioned for effective treatment of COVID-19 in all phases, from the mildest to the most severe.

Synthesis of imatinib, a tyrosine kinase inhibitor, labeled with carbon-14

Imatinib (Gleevec) is a multiple tyrosine kinase inhibitor that decreases the activity of the fusion oncogene called BCR-ABL (breakpoint cluster region protein-Abelson murine leukemia viral oncogene homolog) and is clinically used for the treatment of chronic myelogenous leukemia and acute lymphocytic leukemia. Small molecule drugs, such as imatinib, can bind to several cellular proteins including the target proteins in the cells, inducing undesirable effects along with the effects against the disease. In this study, we report the synthetic optimization for 14 C-labeling and radiosynthesis of [14 C]imatinib to analyze binding with cellular proteins using accelerator mass spectroscopy. 14 C-labeling of imatinib was performed by the synthesis of 14 C-labeld 2-aminopyrimidine intermediate using [14 C]guanidine·HCl, which includes an in situ reduction of an inseparable byproduct for easy purification by HPLC, followed by a cross-coupling reaction with aryl bromide precursor. The radiosynthesis of [14 C]imatinib (specific activity, 631 MBq/mmol; radiochemical purity, 99.6%) was achieved in six steps with a total chemical yield of 29.2%.

Synthesis, in vitro and in vivo evaluation of 18F-fluoronorimatinib as radiotracer for Imatinib-sensitive gastrointestinal stromal tumors

INTRODUCTION

Gastrointestinal stromal tumors (GIST) have a wide range of mutations, but can mostly be treated with Imatinib, until eventually resistance towards this tyrosine kinase inhibitor is acquired. Early and non-invasive determination of the sensitivity of the tumor and its metastases towards Imatinib by positron emission tomography (PET) would be beneficial for therapy planning and monitoring.

METHODS

We developed a synthesis strategy towards the precursor molecule, performed the ¹⁸F-synthesis and in the following evaluated the radioligand in vitro regarding its lipophilicity, stability and biological activity (KIT binding properties) as well as its in vivo properties in GIST tumor-bearing mice.

RESULTS

[¹⁸F]fluoronorimatinib could be obtained in an overall radiochemical yield of 22.2±3.3% within 90min. The radioligand showed high GIST cell uptake and was able to distinguish between Imatinib-sensitive and resistant tumor cell lines (GIST-T1, GIST882, GIST430) in vitro. Further biological evaluations of the ligand towards 9 different GIST-relevant KIT mutations showed comparable binding affinities compared to the structural lead Norimatinib (65nM vs. 53nM for wt-KIT). The in vivo evaluation of the newly developed radioligand showed tumor-to-background-ratios comparable to previously described, similar radiotracers.

CONCLUSIONS

Thus, [¹⁸F]fluoronorimatinib is able to distinguish between Imatinib-resistant and sensitive KIT mutations. Although no improvement of in vivo tumor-to-background ratios could be achieved compared to formerly described radioligands, the hepatic uptake could be considerably reduced, being advantageous for the imaging of GIST. Advances in knowledge and implications for patient care: We were able to show that it is possible to significantly reduce the unfavorably high hepatic uptake of small-molecule radioligands applicable for GIST PET imaging. This work can thus be the basis for further work intending to develop a PET-radioligand for Imatinib-dependent GIST imaging.

An optimized approach in the synthesis of imatinib intermediates and analogues

We revisited the classical synthetic procedure for imatinib synthesis providing an improved and optimized approach in the preparation of a series of new imatinib analogues.

Green chemistry approaches as sustainable alternatives to conventional strategies in the pharmaceutical industry

Green chemistry is a rapidly developing field for the sustainable development of future science and technology. Incorporating green chemistry into the synthesis of active pharmaceutical ingredients and intermediates is of ongoing importance to the pharmaceutical industry.

Tyrosine kinase inhibitor Thiotanib targets Bcr-Abl and induces apoptosis and autophagy in human chronic myeloid leukemia cells

Chronic myeloid leukemia (CML) is characterized by abnormal Bcr and Abl genes and enhanced tyrosine kinase activity. Anti-CML therapy has been much improved along with the applications of tyrosine kinase inhibitors (TKIs) which selectively target Bcr-Abl and have a cytotoxic effect on CML. Recently, four-membered heterocycles as "compact modules" have attracted much interest in drug discovery. Grafting these small four-membered heterocycles onto a molecular scaffold could probably provide compounds that retain notable activity and populate chemical space otherwise not previously accessed. Accordingly, a novel TKI, Thiotanib, has been designed and synthesized. It selectively targets Bcr-Abl, inducing growth inhibition, cell cycle arrest, and apoptosis of CML cells. Meanwhile, the compound Thiotanib could also induce autophagy in CML cells. Interestingly, inhibition of autophagy promotes Thiotanib-induced apoptosis with no further activation of caspase 3, while inhibition of caspases did not affect the cell survival of CML cells. Moreover, the compound Thiotanib could inhibit phosphorylation of Akt and mTOR, increase beclin-1 and Vps34, and block the formation of the Bcl-2 and Beclin-1 complex. This indicates the probable pathway of autophagy initiation. Our results highlight a new approach for TKI reforming and further provide an indication of the efficacy enhancement of TKIs in combination with autophagy inhibitors.