VIETNAM GENERAL CONFEDERATION OF LABOUR TON DUC THANG UNIVERSITY FACULTY OF APPLIED SCIENCE LE QUOC TUAN SYNTHESIS AND ANTIPROLIFERATIVE EVALUATION OF N- ALKYLATED (2-(4- METHOXYPHENYL)-1H- BENZO[D]IMIDAZOL-5(6)- YL)(PHENYL)METHANONE DERIVATIVES UNDERGRADUATE THESIS OF CHEMICAL ENGINEERING ORGANIC SYNTHESIS HO CHI MINH CITY, YEAR 2023 VIETNAM GENERAL CONFEDERATION OF LABOUR TON DUC THANG UNIVERSITY FACULTY OF APPLIED SCIENCE LE QUOC TUAN- 61602260 SYNTHESIS AND ANTIPROLIFERATIVE EVALUATION OF N- ALKYLATED (2-(4- METHOXYPHENYL)-1H- BENZO[D]IMIDAZOL-5(6)- YL)(PHENYL)METHANONE DERIVATIVES UNDERGRADUATE THESIS OF CHEMICAL ENGINEERING ORGANIC SYNTHESIS Advised by Assoc. Hoang Thi Kim Dung M., Phan Ngoc Kim Ngan HO CHI MINH CITY, YEAR 2023 ACKNOWLEDGMENT I sincerely thank all Faculty of Applied Sciences lecturers who provided me with valuable information in their respective fields. Headforemost, I want to express my thankful gratitude to Assoc. Hoang Thi Kim Dung, for all of her guidance and support throughout the writing of my thesis and her kindness, patience, and knowledge.
In addition to writing and conducting academic research in organic chemistry, I have received many helpful and constructive recommendations about my field. Additionally, I would like to thank Ms. Phan Ngoc Kim Ngan, who has supported and managed my project and has been encouraging and instructive throughout the research. Her extensive knowledge and academic guidance were crucial in assisting me in completing my thesis.
Besides, I'd like to thank everyone in the Organic Chemistry and Polymer department for their continued friendliness and assistance during the period with report documents and presentations. Finally, I sincerely thank my family, especially my parents. Through every accomplishment in my life, they have always been there for me with their unconditional love and wholehearted support. Ho Chi Minh City, day … month … 2023 Author This thesis was carried out at Ton Duc Thang University.
Hoang Thi Kim Dung M., Phan Ngoc Kim Ngan This thesis is defended at the Undergraduate Thesis Examination Committee was hold at Ton Duc Thang University on… Confirmation of the Chairman of the Undergraduate Thesis Examination Committee and the Dean of the faculty after receiving the modified thesis (if any). CHAIRMAN DEAN OF FACULTY. DECLARATION OF AUTHORSHIP I hereby declare that this thesis was carried out by myself under the guidance and supervision of Assoc. Hoang Thi Kim Dung, and that the work and the results contained in it are original and have not been submitted anywhere for any previous purposes.
The data and figures presented in this thesis are for analysis, comments, and evaluations from various resources by my own work and have been duly acknowledged in the reference part. In addition, other comments, reviews, and data used by other authors and organizations have been acknowledged, and explicitly cited. I will take full responsibility for any fraud detected in my thesis. Ton Duc Thang University is unrelated to any copyright infringement caused on my work (if any) Ho Chi Minh City, day month year Author i ABSTRACT In this thesis, ten (2-(4-methoxyphenyl)-1H-benzo[d]imidazol-5(6)- yl)(phenyl)methanone derivative was successfully synthesis via condensation of the o-phenylenediamine derivative with aromatic aldehyde derivative in the presence of Na2S2O5 using the mixed solvent of EtOH: H2O (9:1, v/v).
Subsequently, ten derivatives of N-alkylated benzimidazole were designed and synthesized by alkylation reactions in the presence of K2CO3 using dimethyl sulfoxide as a solvent. All synthesized compounds were characterized by HPLC, UV-Vis, FT-IR, 1D and 2D-NMR, and HRMS. The antiproliferative test determined activity against a human breast cancer cell line (MDA-MB-231) by the SRB method. The results revealed that compounds 3, 6b, and 6d displayed antiproliferative activities against tested cancer cell line with IC50 values ranging from 48,58- 70,93 M.
TÓM TẮT Trong luận văn này, 10 dẫn xuất của (2-(4-methoxyphenyl)-1H- benzo[d]imidazol-5(6)-yl)(phenyl)methanone đã được tổng hợp thành công bằng phản ứng ngưng tụ giữa dẫn xuất của o-phenylenediamine và dẫn xuất aldehyde thơm có sử dụng xúc tác Na2S2O5 trong hỗn hợp dung môi EtOH: H2O (9:1, v/v). Sau đó, mười dẫn xuất alkyl hóa tại vị trí N-1 của benzimidazole được tổng hợp bằng phản ứng alkyl hóa với xúc tác K2CO3 trong dung môi DMSO. Các hợp chất đã tổng hợp được xác định tính chất bằng HPLC, UV- Vis, FT- IR, 1D và 2D- NMR, và HRMS. Khả năng ức chế tăng sinh tế bào được thử nghiệm trên dòng tế bào ung thư vú MDA- MB-231 bằng phương pháp SRB.
Kết quả thử nghiệm cho thấy hợp chất 3, 6b và 6d thể hiện hoạt tính ức chế sự phát triển của dòng tế bào ung thư nghiên cứu với giá trị IC50 từ 48. ii CONTENTS ABSTRACT. i LIST OF FIGURES .v LIST OF SCHEMES. vi LIST OF TABLES.
vii LIST OF ABBREVIATIONS. Overview to 2,5(6)-disubstituted benzimidazole derivatives. Overview to N- alkylated benzimidazole derivatives. Synthesis of N- alkylated.
Materials and instrumentations. Procedure for synthesis of (2-(4-methoxyphenyl)-1H-benzo[d]imidazol-5(6)- yl)(phenyl)methanone (3). General procedure for the synthesis of N- alkylated (2-(4-methoxyphenyl)- 1H-benzo[d]imidazol-5(6)-yl)(phenyl)methanone derivatives. Isolation method and structure determination .21 CHAPTER 3: RESULT AND DISCUSSION .2 N- alkylated (2-(4-methoxyphenyl)-1H-benzo[d]imidazol-5- yl)(phenyl)methanone derivatives.
Suggestion on future work .57 v LIST OF FIGURES Figure 2.1 Illustration of procedure for synthesizing compound 3 .2 Illustration of procedure for synthesizing 5a-e and 6a-e .1 Sample and TLC of 3 .2 Sample and TLC of 5a .3 Sample and TLC of 5b .4 Sample and TLC of 6b .5 Sample and TLC of 5c .8 Sample and TLC of 6c .7 Sample and TLC of 5d .8 Sample and TLC of 6d .9 Sample and TLC of 5e .10 Sample and TLC of 6e .11 UV-Vis absorption spectra of compounds 3, 5a−e, 6a−e.12 1H-NMR spectra of compound 6b (A) and compound 5b (B) Figure 3.13 2D-NMR spectra of 6b. a) NOESY spectrum, correlations between H-7 and H-1” are circled in red color. b) HMBC spectrum, correlations between H-1” and C-2 and C-8 are circled in blue color.14 2D-NMR spectra of 5b. a) NOESY spectrum, correlations between H-7 and H-1” are circled in red color.
b) HMBC spectrum, correlations between H-1” and C-2 and C-8 are circled in blue color. vi LIST OF SCHEMES Scheme 1.1 Benzimidazole structure and numbering rule .2 Phillips's reaction of o-phenylenediamine and oxalic acid .3 Reaction of o-phenylenediamine with anhydride acetic .4 Reaction of 3,4- diamino-toluene with ethyl formate .5 Reaction of aryldiamine with 4-hydroxy-5,8-dimethoxy-2- naphthaldehyde .6 Reaction of o-phenylenediamnie with aldehyde .7 Benzimidazole synthesis by oxidation of air .8 Benzimidazole synthesis with microwave- assisting .9 General structures of compounds 1-6 .10 Compounds 4a and 4b in the study of Nayak et al.11 Structures of compounds 38 and 40 .12 Alkylation reaction of Nale et al.13 Alkylation reaction of Chakraborty et al.14 Structure of compound 4k .15 Structure of compound TJ08 .16 Structure of compound 4c .1 Procedure for synthesis of 3 .2 General procedure for the synthesis of 5a-e, 6a-e .1 General procedure for the synthesis of the final compounds 5a−e, 6a−e. Mechanism of the alkylation reaction .25 vii LIST OF TABLES Table 1.1 Marketed medicines containing benzimidazole moiety .2 IC50 values of compounds 38 and 40 against MDA-MB-231 .3 IC50 values of compound TJ08 against six cancer cells and normal cells .4 List of chemicals .5 List of instrumentations .7 NMR techniques for structure determination were used in this thesis.1 Yield of synthesized .2 Comparison between the 1H-NMR chemical shift of this study with previous reports.3 IC50 of synthesized compounds (3, 5a-e, 6b-e). 52 viii LIST OF ABBREVIATIONS EA ethyl acetate Chemical shift d doublet dd doublet of doublets DI Water Deion water DMSO dimethyl sulfoxide dt doublet of triplets EtOH ethanol FT- IR Fourier transform Infrared spectroscopy Hex n- hexane HMBC Heteronuclear Multiple Bond Coherence HPLC High- performance Liquid Chromatography HRMS High-Resolution Mass Spectroscopy HSQC Heteronuclear Single Quantum Coherence J Coupling constant m multiplet MeCN acetonitrile MeOH methanol NMR Nuclear Magnetic Resonance Spectroscopy Rf retardation factor s singlet t triplet TCA trichloracetic acid TLC Thin Layer Chromatography tt triplet of triplets 1 INTRODUCTION 1.
Introduction Cancer is one of the fatal causes of death worldwide, necessitating the development of novel and effective treatments. Even though modern therapeutic agents have been developed over the last 100 years, the successful treatment of cancer appears to be a formidable challenge at the start of the century. According to GLOBOCAN's 2020 forecast, approximately 19.3 million cancer diagnoses and 10 million cancer deaths are predicted worldwide in 2020. Breast cancer (BC) is 1 in 4 commonly diagnosed cancers and the second most significant cause of cancer-related deaths in women; about 12% of breast cancers are triple negative.
This obstacle results from the challenges of discovering innovative selective medicines that suppress tumor cell development without being harmful to normal cells. Historically, nitrogen-containing heterocycles are an exciting research topic because they are bioactive compounds. Due to their reputation, N-heterocycles are essential for studying biological activities. Among them, benzimidazoles greatly interest many research groups investigating drug development.
Mounting evidence indicates that benzimidazole and its derivatives, with substitutions at the 1, 2, 5, and/or 6-positions, have a vast medicinal profile in multiple categories of therapeutic agents with unique properties, including antimicrobial,anti-hypertensive, anti- tuberculosis, anti-viral, antiulcer, anti-inflammatory, anti-diabetic, anti-convulsant and anti-malarial. In addition, many studies already reveal the potential of benzimidazole derivatives as anticancer medicines. In our previous work, benzimidazole derivatives have been synthesized, and in terms of anticancer activities, (2-(4-methoxyphenyl)-1H-benzo[d]imidazol-5(6)-yl)(phenyl)methanone emerged as multitarget anticancer agent, especially in anticancer effect against breast cancer cell line (MDA-MB-231). Encouraged by these findings, in this study, we considered introducing the alkyl straight chains to the benzimidazole moiety to produce new molecules with the expectation of increasing anticancer activity.
Aims and objectives With the above preamble, the present work entitled "Synthesis and antiproliferative evaluation of N- alkylated (2-(4-methoxyphenyl)-1H- benzo[d]imidazol-5(6)-yl)(phenyl)methanone derivatives" has been done with the following objectives: i. Dealing with developing a method for synthesizing benzimidazole and N-alkylated benzimidazole derivatives and characterizing them by physical and spectral analysis. Dealing with evaluating synthesized derivatives for antiproliferative activity against breast cancer cell line (MDA-MB-231). The objective of the current work has been aimed at achieving the following, i.
To synthesize a nucleus containing benzimidazole. To synthesize targeted N-alkylated benzimidazole isomers. To isolate the N-alkylated benzimidazole derivative in a mixture of positional isomers. To establish the structure based on melting point, UV-Vis, FT-IR, NMR, and HRMS spectra.
To evaluate compounds for antiproliferative activity. Introduction Benzimidazole is a compound consisting of a phenyl ring attached to an imidazole ring that was first synthesized by Hoebrecker by reduction of 2-nitro-4- methylacetanilide to obtain 2,5(or 2,6)- dimethylbenzimidazole in 1872 [1]. In the following years, Ladenburg and Philip found synthetic pathway of benzimidazole by condensing o-phenylenediamine with carbonyl group compounds. Therefore, the preparation of benzimidazole from ortho-amino aniline is referred to as the Ladenburg method, Phillips’s method [2], [3].
In 1949, Brink et al. proved the appearance of a benzimidazole scaffold as the ligand during the degradation of vitamin B12. Consequently, the connection between benzimidazole structure and biological activities was identified [4]. Benzimidazole structure and numbering rules are described in Scheme 1.1 Benzimidazole structure and numbering rule Due to tautomerization, 1H-benzimidazole derivatives exist as isomers.
The two derivatives, 5-methylbenzimidazole, and 6-methylbenzimidazole, illustrate a pair of tautomers and describe the same substance. However, no tautomerization occurs when a substituent at the N-1 position is larger than the hydrogen, but a characteristic isomer forms [1]. Physicochemical properties The benzimidazoles are simply solids with relatively high melting points (1H- benzimidazole, 170°C). Generally, when a substituent is added to the N-1 position, the melting point of benzimidazoles decreases (1-methyl-1H-benzimidazole, 66oC) [5] because benzimidazoles cannot form intermolecular hydrogen bonds because the hydrogen is at N- 1 was replaced.
4 The 1H-benzimidazoles are highly soluble in polar solvents and sparingly soluble in nonpolar solvents. When substituents of different polarities are attached to the benzimidazole ring, they are soluble in the respective solvent. For example, 2- methylbenzimidazole is well-soluble in the ether, while 2-aminobenzimidazole is highly soluble in water [14]. Application Benzimidazole derivatives have been applied in a variety of industries: textile dying [6], semi-conduction [7], and anti-corrosion [8],.
