Process Research Of Osimertinib And Design,Synthesis And Preliminary Activity Study Of EGFR And HDACs Dual-Target Inhibitors

Malignant tumor is one of the most serious diseases threating human health,the pathogenesis of which 1s extremely complex.The tumors also have characteristics of recurrence and netastasis.The conventional therapeutic options like radiotherapy and chemotherapy are limited due to the dose-lirruted cytotoxicity.With the deepening research on malignant tumor lesions,a variety of therapeutic targets have been found.The epidermal growth factor receptor(EGFR),a representative kinase receptor,has become a star target for the research of anti-tumor drugs.EGFR is a transmembrane receptor widely distributed on the human cell membrane with the tyrosine kinase domain residing on the intracellular region ot EGFR.Upon binding with adenosine triphosphate(ATP),the tyrosine kinase domain can phosphorylate the specific tyrosine residues.So the aotophorylation of EGFR occurs.activating the downstream signal pathways and mediating cell growth.proliferaton and differentiation.Abnormal expression or overexpression of EGFR have bccn found in a variety of human tumor cells.So tan four monoclonal antibodies and five small molecule inhibitors targeting RGFR have obtained the FDA approval for cancer treatment.These drugs interfere with the cell signal transduction through "upstream intervention" or "downstream interference",and then inhibit tumor growth.A challenge to the development and clinical application of EGFR tyrosine kinase inhibitors is drug resistance.Osimertinib is the only third-generation inhibitor which got the FDA approval for the treat:ent of patients with metastatic EGFR T790M mutation-positive NSCLC.Osimertinib contains an electrophilic acrylamide chain,which could covalently bind to 797 cysteine of EGFR harboring T790M mutation via a Michael addition,thus leading to sustained EGFR inhibition and anti-tumor effect.Although conquering the resistance induced by gefitinib and erlotinib,osimertinib ultimately develop resistance because of the C797S mutation,which makes the activity-conferring covalent bond unavailable,and results in drug resistance.The C797S mutation has also been found in clinical trials of other third-generation EGFR inhibitors.HDACs is an important anti-tumor target associtated with epigenetic modification.There are currently four HDAC inhibitors approved by the FDA.Studies have shown that HDAC inhibitors could inhibit the binding of transcription factor SP1 to the promoter of genes encoding EGFR.thereby reducing EGFR expression.This provides a theoretical basis for the design and synthesis of EGFR/HDAC dual target inhibitors.In this paper,our work is focused the study of Osimertinib and its derivatives.In the first part,we studied the synthesis process of osimertinib.On the basis of literature research,we designed two newly synthetic routes of osimertinib,and then we optimized the conditions of synthetic reaction.After optilization,we got mild reaction conditions and could separate and purify intermediate and end-product in a simple way like recrystallization.After further optimization,the total yield of route 3 reached 42%,which is close to the original route of Osimertinib,and the purity of the product was more than 99.5%.In the second part、in view of the relationship between HDAC and EGFR.based on the multi-target drug design strategy.we designed and synthesized 12 new compounds containing Osimertinib’s aninopyrimidine scaffold.The structures of target compounds were confirmed by NMR and HRMS.Then the prelilinary biological activity of these new compounds were evaluated.In HDACs inhibition assay,compounds YH-4,YH-5,YH-11and YH-12 displayed superior HeLa cell nuclear extract(HDAC1,HDAC2)inhibitory activity than the positive control SAHA.In vitro anti-proliferation assays showed that representative compounds YH-12 exhibited comparable anti-proliferative activities against multiple solid and hematologic tumor cells to Osimertinib.In particular,breast cancer cell lines MDA-MB-231 and MDA-MB-468 and hematocrit cell line KG-1 are the most sensitive cell lines to our compounds with IC50 values of 0.60μM,0.23μM and 0.24μM,respectively.