Synthesis Of Novel Pyrimidine Compounds And Their Inhibitory Activity On Tumor Cell Proliferation

Pyrimidine derivatives,as one of strong physiological activities,not only have high application value in modern agriculture,but also have been widely used in biomedicine.With the continuous exploration and research of pyrimidine derivatives in the treatment of tumor,the emergence of the third generation of tyrosine kinase inhibitor with a pyrimidine backbone has brought potent benefits to patients with cancer.However,the drug resistance have appeared after long-term use,which would lead the therapeutic effect significantly reduce.Therefore,it is urgent to find the new anti-tumor drugs with high-efficient and low toxic.In this study,a series of new pyrimidine derivatives were designed and synthesized,and the structures of target compounds were characterized by nuclear magnetic resonance（NMR）,infrared spectroscopy（IR）,and high resolution mass spectrometry（HRMS）.Finally,a preliminary antiproliferative activities of the synthesized compounds were testd against human tumor cell,and the druggability of higher activity compounds were predicted.The main contents are as follows.（1）On the basis of reviewing literature,it was discussed for the structures,the synthesis methods and the anti-tumor activities of pyrimidine and its derivatives.According to the anti-tumor application of pyrimidine compounds and the previous research results from our laboratory,the new pyrimidine derivatives with low toxicity and high efficiency will be found by further derivatization from pyrimidine as core structure.Therefore,34 new pyrimidine derivatives were designed by the introduction of morpholine or N-methylpiperazine unit linked with oxygen or sulfur atom and a carbon chains including two or three carbon atoms at the 2-position of pyrimidine,and five arylamino groups at the 4-position of pyrimidine,respectively.（2）The needed intermediates for the synthesis of the target compounds were prepared according to the previous research of our laboratory.Five kinds of 4-arylaminopyrimidine intermediates were prepared by the nucleophilic substitution reaction of 2,4-dichloropyrimidine with five arylamines,such as 3-chloro-4-fluoroaniline,3-ethynylaniline,3-chloro-4-（3-fluorobenzyloxy）aniline,3-chloro-4-（pyridin-2-ylmethoxy）aniline and 3-chloro-4-（3-（trifluoromethyl）phenoxy）aniline,in the presence of triethylamine as acid-binding agent in N,N-dimethylformamide（DMF）.The reation yield is 60%-82%（3）To obtain required hydrophilic structural units in the target molecules,4-hydroxyethylmorpholine or 1-（2-hydroxy ethyl）-4-methylpiperazine was respectively synthesized with a yield of 57%-87%by the reactions of morpholine or N-methylpiperazine with bromoethanol.And a subsequent reaction with thionyl chloride（SOCl2）gave 4-（2-chloroethyl）morpholine hydrochloride and 1-（2-chloroethyl）-4-methylpiperazine hydrochloride in 76%-84%yield.Morpholine or N-methylpiperazine were reacted with 1-bromo-3-chloropropane to give 4-（3-chloropropyl）morpholine and 1-（3-chloropropyl）-4-methylpiperazine in 80%-92%yield.Meanwhile,morpholine or N-methylpiperazine reacted with bromopropanol to prepare 4-hydroxypropylmorpholine or 1-（3-hydroxypropyl）-4methylpiperazine in 87%-90%yield.（4）Thirty-four target compounds were synthesized.In the synthesis of the target compounds with hydrophilic structural unit linked with S atom,the obtained four kinds of chlorinated compounds reacted firstly with thiourea in DMF to give four kinds of isothiourea salts.Then,the isothiourea salt reacted respectively with five 4-arylaminopyrimidine intermediates in the mixed solvent of DMF and water in the presence of K2CO3 as acid-binding agent to obtain eighteen target pyrimidine derivatives with the yield of 30%-70%.In the synthesis of the target compounds with hydrophilic structural unit linked with O atom,the obtained 4-hydroxyethylmorpholine,1-（2-hydroxy ethyl）-4-methylpiperazine,4-hydroxyPropylmorpholine and 1-（3-hydroxypropyl）-4-methylpiperazine reacted respectively with 4-arylaminopyrimidine intermediate in dioxane or diethylene glycol dimethyl ether in the presence of sodium or potassium hydroxide to give sixteen target pyrimidine derivatives with the yield of 20%-70%.（5）With the clinical anticancer drug Gefitinib as a positive control,the antiproliferative activities of these target compounds were evaluated by MTT assay against four human tumor cells,including colon cancer SW480,epidermal squamous cell carcinoma A431,non-small cell lung cancer A549 and human lung cancer NCI-H1975.The results showed that most of the synthesized pyrimidine derivatives have inhibitory effects on the proliferation of four kinds of cancer cell lines.Especially compounds B9,B23,B25,B26,and B28 exhibited better antiproliferative activities.Its IC50 values against the four cell lines are respectively 2.80-9.55,1.63-10.41,2.74-4.31 and 3.86-10.82μM.While the IC50 values of Gefitinib against the four cell lines are 13.85±1.44,18.36±2.02,5.22±0.82 and 11.60±0.05 μM,respectively.These resluts indicated the antiproliferative activities of compounds B9,B23,B25,B26,and B28 against four tumor cells were more potent than that of Gefitinib.（6）The druggabilities of compounds B23 and B25 with best anti-proliferative activity against tumor cells were predicted from Lipinski rule,absorption,distribution,metabolism and excretion（ADME）etc.Compared with the predicted resluts of the clinical anticancer drugs Gefitinib,Lapatinib and Osimertinib,it is suggested that compounds B23 and B25 have the potential to become medicines and have the value of further research.