Design,Efficient Synthesis And Biological Evaluation Of Isoindolinone Derivatives Targeting COX-1/COX-2

Thromboinflammation refers to pathological responses following blood vessel injury,invasion by a variety of pathogens,or non-infectious inflammatory triggers,which is associated with various cardiovascular diseases,such as stroke,deep vein thrombosis,myocardial infarction,disseminated intravascular coagulation,and among others.The monotherapy,namely treatment for inflammation or thrombosis,is incurable,only partially preventing or reversing thromboinflammation.Cyclooxygenases（COXs）are enzyme complexes that play a crucial role in the inflammatory process and cardiovascular system.Their inhibitors are widely used in anti-platelet aggregation（selective COX-1 inhibitor）and anti-inflammatory（selective COX-2 inhibitors）.The balanced COX inhibitors with anti-platelet aggregation and anti-inflammatory activities could be served as a promising therapeutic strategy for thromboinflammation.Indobufen is an anti-platelet aggregation agent that selectively inhibits COX-1,being used in clinical for the treatment of ischemic cardiovascular disease,venous thrombosis caused by arteriosclerosis,and thrombosis prevention during hemodialysis in clinical.Herein,by using Indobufen as the lead compound,we described the structural modification at the C-7 position based on computer-aided drug design.By installing functional groups,like amides and sulfonamides,we aimed to adjust their selectivity and inhibitory activity on COX-1 and COX-2,thereby exhibiting both anti-platelet aggregation and anti-inflammatory activities,which may be the potential therapeutic drugs for thromboinflammation.In this study,we developed synthetic methodologies for the installation of functional groups at the C-7 position and thus efficient synthesized 61isoindolinone derivatives.The resulting compounds were carefully characterized by melting point,nuclear magnetic resonance(¹H NMR,¹³C NMR,and ¹⁹F NMR),high-resolution mass spectrometry（HRMS）,and high-performance liquid chromatography（HPLC）.In addition,their corresponding biological activities,such as cyclooxygenase inhibition assays,anti-platelet aggregation and anti-inflammatory properties,and in-vivo safety（ulcerogenic liability）were evaluated,respectively.The results suggested that compounds L-32,L-33,L-38,L-52,and L-53 could be the potential molecules for thromboinflammation.The dissertation is organized as follows:1.Direct amidation at the C-7 position of isoindolinone skeleton.In chapter 1,we described a copper-promoted cross-dehydrogenative coupling reaction for direct amidation of isoindolinone scaffolds by sodium persulfate;Moreover,we have elucidated the reaction mechanism in detail.Because of the mild reaction condition and high site-selectivity,the method was successfully applied to synthesize 35 structurally diverse Indobufen derivatives.2.Synthesis of C-7 amide substituted isoindolinone derivatives by Ritter-type reaction.The Ritter-type reaction,without relying on a pre-installed functional group,is a highly efficient tool for the construction of amides.However,controlling its chemo-selectivity remains challenging.In chapter 2,from 68 different types of hydrates,we found that a coordinatively unsaturated inorganic salt hydrate,Mg SO₄·2H₂O,was capable of controlling chemo-selectivity and eliminating the shortcomings of other synthetic approaches.To rationalize the differences in selectivity of inorganic salt hydrates,we analyzed their corresponding water content,alkalinity,anions,and cations.In addition,the Mg SO₄·2H₂O was used with diverse scaffolds and C-H oxygenations,including Indobufen acetamide derivatives（L-26）,which demonstrated its generality in synthetic utility.3.Direct Sulfonamidation at the C-7 position of isoindolinone skeleton.The sulfonamide bond has been an important motif in medicinal chemistry due to its strong hydrogen bond association,chemical and metabolic stability,etc.Based on the results of computer-aided drug design,the installation of the sulfonamide group at the isoindolinones C-7 position can enhance the binding affinity to COX-2,which improves its anti-inflammatory activity.As a consequence,we described a direct sulfonamidation of isoindolinone skeleton via water-promoted oxidative hydroxylation-nucleophilic substitution cascade reaction and synthesized 8 Indobufen derivatives.4.Biological evaluation of isoindolinone derivatives.In chapter 4,we have also prepared 18 structurally diverse isoindolinone derivatives for the structure-activity relationship study.Next,we evaluated the prepared 61 isoindolinone derivatives for their cyclooxygenase inhibition assays,anti-platelet aggregation and anti-inflammatory activities in vitro,and in-vivo safety（ulcerogenic liability）,respectively.Among them,compounds L-32,L-33,and L-52 not only exhibit potent anti-platelet aggregation activity but also better anti-inflammatory activity than the reference drug Indobufen.In addition,despite the weak antiplatelet aggregation activity,L-38 and L-53 showed higher COX-2inhibitory and anti-inflammatory activity than Indobufen.Notably,these five compounds proved to have a better gastrointestinal safety profile compared to Indobufen and Indomethacin,which could be promising drug candidates for thromboinflammation therapy.