Design And Synthesis Of Multi-substituted Pyrimidine Ketones As HCV NS5B Polymerase Inhibitors

Hepatitis C virus(HCV)is considered to be the aetiology(including liver cirrhosis and liver function failure),which causes the hepatitis C infected cells,hepatocellular carcinoma and chronic liver disease.Since the discovery of hepatitis C virus,about 200 million people is now estimated to be HCV chronic infection in all over the world,accounting for 3%of the world’s population.HCV has become a serious public health threat to human health.Any interference or inhibition on any link of HCV replication process can be likely to effect on the treatment of HCV infection,including a variety of enzymes in the replication process,which become the targets of anti HCV drugs.The HCV drug has been developing rapidly since 2011.Currently,listed on HCV drugs mainly NS3/4A inhibitors,NS5A inhibitors and NS5B inhibitors.We have focused our work on design and synthesis pyrimidine ketone as anti-HIV inhibitors for a long time.In recent years,due to the serious HIV and HCV co-infection,we have been trying to find the active molecules inhibiting both on HIV and HCV.In this paper,by using methods of computer aided drug design,a series of(Z)-6-benzyl/cyclohexyl-5-ethyl-2-((2-(4-substituted phenyl)-2-(hydroxyimino/hydrazino)methyl-thio)pyrimidin-4(3H)-ones(I),6-cyclohexyl/phenyl-5-al-kyl/cyano-2(a-bromo-4-substit-uted phenylaceta-mide)pyrimidin-4(3H)-ones(Ⅱ),6-cyclo-hexyl/phenyl-5-alkyl/cyano-2(4-(2-bromoacetyl)substitute dester)pyrimidin-4(3H)-ones(Ⅲ)comp-ounds were designed and synthized.The structure activity relationship will be further studied based on the activity test.The first chapter introduces the structure and replication cycle of HCV,briefly introduces the main targets of anti HCV drugs and mainly overviews the research progress of nonnucleosides HCV NS5B polymerase inhibitors.In second chapter,the binding site between HCV NS5B polymerase and three anti-HCV active polysubstituted pyrirnidinone compounds synthized in our laboratory were anaylzied by using molecular docking method.,The analysis results were further used to design the structures of the target compounds.like fixing ring structre,retaining the original efficacy and embellishing the structure of C-2,C-5 and C-6 of the lead compounds:(1)Introducing substituent groups of different volume or electrical properties in C-2 site,it can help to enhance the hydrogen bond,hydrophobicity and л-лinteractions between the target molecule and the amino acid residues.(2)C-5 region is a hydrophobic,polar area,which can enhance the hydrogen bonding interactions,electrostatic and steric effects between drug molecules and amino acids by introducing hydrophobic group,polar group and hydrogen bond/acceptor(3)C-6 site is a hydrophobic area where can be introduced flexible C-6ω-cyclohexyl,changed the bond length between C-6 and cyclohexyl to strengthen the Vander Waals force and then improve the resistance;It can also be introduced rigid benzene ring to strengthen л-лinteraction between molecular compound and surrounding aromatic residues.Multi substituted pyrimidinone compounds were structured on the above design idea,such as series(Z)-6-benzyl/cyclohexyl-5-ethyl-2-((2-(4-substitutedph-enyl)-2-(hydroxyim ino/hy-drazino)methylthio)pyrimidin-4(3H)-ones(I),6-cyclohexyl/phenyl-5-alkyl/cyano-2(a-bromo-4-substituted phenylacetamide)pyrimidin-4(3H)-ones(Ⅱ)and 6-cyclohexyl/phe-nyl-5-alkyl/cyano-2(4-(2-bromoacetyl)substituted ester)pyrimidin-4(3H)-ones(Ⅲ).In third chapter,the 5-alkyl-6-Cyclohexyl(cyclohexyl methyl/phenyl/benzyl/)pyrimidine was synthesized by close-loop condensation reaction of thiourea with the key intermediate-β-ketone ester,which was prepared by using the modified clay route,with the formic acid/acetic acid/aromatic acid as the raw material..The 5-Cyano pyrimidine ketone was prepared in Biginelli one-step synthesis method.The 5,6-substituted pyrimidine ketone react with a-bromo-4-substituted phenyl amide and 4-(2-acetyl acetyl)substituted acid ester catalyzed by K2CO3 to get the 6-cyclohexyl/phenyl-5-alkyl/cyano-2(alpha-bromo-4-substituted benzene acetamide)pyrimidin-4(3H)-ketones(Ⅱ)and 6-cyclohexyl and phenyl-5-alkyl/cyano-(4-(2-acetyl bromide)substituted ester)pyrimidin-4(3H)-ketones(Ⅲ)series of compounds.On another way,the 6-benzyl/cyclohexyl-5-ethyl-2-((2-(4-substituted phenyl)-2-oxo ethyl mercaptan)pyrimidin-4(3H)ketone intermediates react with HO-NH2.HCl or H2O.NH2-NH2 to get the series I target compounds.Totally,38 S-DACOs class new target compounds were synthesized in this paper,the structures of the target compounds were characterized by 1H NMR,13C NMR,FT-IR and ESI-MS.The fourth chapter,the target compound N-(2,4-difluorophenyl)-2-((5-ethyl-6-oxo-4-phenyl-1,6-dihydro-2-yl)thio)acetamide(ZY-03)and 6-benzyl-5-ethyl-2-(2-hydroxyimino-2-phenyl-ethylthio)-3H-pyrimidin-4-one(ZY-34)are carried out a detailed analysis with1H NMR,13C NMR,FT-IR and ESI-MS,while the single-crystal X-ray structure of ZY-34 was also be analyzed.The fifth chapter introduces the method of testing the anti HCV activity.The anti HCV activity of the compound was completed by Xia Xueshan,a professor of life sciences at the Kunming University of Science and Technology,which is still in the testing.