Research Article

Synthesis and Antimicrobial Activity of 2-(substituted)-4-[2-(10-p-chlorobenzyl) phenothiazinyl]-6-(substituted aryl)pyrimidines

Megha Sharma
N.R.E.C. College, India
* Corresponding author
Sanidhyay Upadhyay
N.R.E.C. College, India
DOI icon 10.24018/ejchem.2024.5.5.108

Read Counter
391

Downloads
85

Citations

Share

Article Sidebar

Submitted 2022-06-24
Published 2024-12-12

Read counter = 391 times

Table of Contents

Article Main Content

A series of novel 2-(substituted)-4-[2-(10-pchlorobenzyl)phenothiazinyl]-6-(substituted aryl)pyrimidines have been synthesized by cyclocondensation of chalcones, obtained by the interaction of 2-acetyl phenothiazine with substituted aromatic aldehydes, with urea, thiourea, and guanidine. Structures of title compounds were elucidated by their IR, 1H NMR spectral data, molecular weight determination, and microanalyses. Antimicrobial activities against gram-positive and gram-negative bacteria were evaluated by the Filter Paper Disc Method.

Keywords: Antimicrobial activity Phenothiazine Pyrimidines

Introduction

Pyrimidines have been identified as better ones among various types of heterocycles owing to their manifold high efficacy of actions. The importance of pyrimidine derivatives is well manifested by the presence of pyrimidine nucleus in vitamin B2 and folic acid, DNA, and RNA [1]. Synthesis of substituted pyrimidine has been reported in several reviews [2]. Moreover, pyrimidine derivatives also exhibit several biological properties viz. antitumor [3], [4], antiviral [5], antifungal [6], anticancer [7], antibacterial [8], anti-inflammator [9], analgesic [10], antagonist [11], [12], antifolate [13], anrimicrobial [14], anti-HIV [15], antiplatelet [16], antifilarial [17], activities etc. In the textile industry, they are promising dyes [18]; in agriculture, derivatives of pyrimidines play vital roles as pesticides and insecticides. In coordination chemistry, pyrimidine compounds have been reported as very effective ligands [19], owing to several donor sites, with transition metals to form complexes.

The high versatility of pyrimidine derivatives in general and those pyrimidinyl heterocyclics containing nitrogen and sulphur hetero atoms, exhibiting a wide range of biological properties, in particular, encouraged us to synthesize new pyrimidine derivatives by the interaction of chalcones [20] with guanidine, urea, and thiourea via condensation route. Structures of new molecules have been assigned on the basis of their microanalyses, molecular weight determination, IR, and 1H NMR. Some of the new compounds have been assayed for their antibacterial properties against some gram-positive and gram-negative bacteria.

Experiment

Melting points of all pyrimidine products were determined by the melting point apparatus with open glass capillaries. Microanalysis of compounds was done at the chemistry department, I.I.T, Roorkee, on Vario-el III, Element-R. Infrared spectra of pyrimidines were recorded in KBr medium in 500 cm−1–4000 cm-1 range on Thermo Nicolet Nexus FT-IR spectrometer at chemistry department, I.I.T, Roorkee whereas 1H NMR spectra of samples were recorded in CDCl3medium at Jamia Hamdard University, Delhi.

General Procedure for Synthesis of Substituted Phenothiazinyl Pyrimidines

Chalcones synthesized earlier from this laboratory [20] have been used as starting materials for the synthesis of substituted phenothiazinyl pyrimidines.

An equimolar (0.01 mol) mixture of chalcone and each of guanidine, thiourea, and urea in dry ethanol (50 ml) was refluxed for 10 h–12 h. During refluxing, aqueous NaOH solution (40%, 5 ml) was added dropwise slowly in 2 h–3 h Scheme 1. The reaction mixture was allowed to stand till acquired at room temperature. The solid product separated was filtered, washed with cold ethanol and water successively, and dried in air.

Antimicrobial Activity of Phenothiozinyl Pyrimidines

Antimicrobial studies on newly synthesized phenothiazinyl pyrimidines were performed using filter paper disc Diffusion method against Enterococus foecium, Enterorcus faecalis, Escherichia coli, and Bacillus subtitles bacteria, and Candida albicans and Axpergillous niger fungi. Whatman filter paper-1 discs (6.5 mm) sterilized by dry heat at 140°C were saturated with test solution placed on surface of sterilized nutrient agar medium for bactericidal study and sabouraud dextrose agar and potato dextrose agar medium for candida albicans and Aspergillus niger respectively for fungicidal study in petri dishes which were preinoculated with test organisms. All these petri dishes were incubated for 48 h, and inhibition zones were measured. Control solvent (tween-80-water,1:9,v/v) was used as blank. The maximum inhibition zone noted is shown in Table III.

Results and Discussion

Molecular weights and microanalysis data are consistent with the deduced molecular formulae of compounds. IR spectra of cyclocondensation products of chalcones with urea, thiour, and guanidine reveal the occurrence of ν C=N band [21] in the range 1625–1674 cm−1 which could be attributed to pyrimidine ring formation. One or two bands in 3384–3445 cm−1, 1178–1209, and 1308–1414 cm−1.

And 3349–3477 cm−1& 1568–1675 cm−1 and 1225–1325 cm−1 and 2562–2594 cm−1 ranges assigned only to νOH, δOH & νC-O, and νN-H & δNH and νC-N (primary amine) and νS-H vibrations respectively obviously indicate the presence of phenolic OH, amino and -SH groups in the products. Besides characteristic bands of pyrimidine ring and its substituents (-OH,-NH2-SH), except ketonic (C=O) and (C=C) chain groups have been found intact in the products (Tables I and II). Aryl para-substituent compounds exhibit their characteristic stretching vibrations in 809 cm−1–848 cm−1range, whereas meta aryl substituents depicted vibrations at ~750 cm−1; νC-Cl observed in the 746 cm−1–776 cm−1 range. In 1H NMR spectra, the disappearance of bands corresponding to >C=CHR and -C-COH=C< of chalcones and peaks of OH, NH, and SH 7.18–7.39 δ, 5.05–5.15 δ and 3.75–3.96 δ regions, respectively observed, confirm the formation of pyrimidine ring.

Elemental analyses %
Compound Color Melting point (C) Yield (%) Molecular weight C H N S
Found Calcd. Found Calcd. Found Calcd Found Calcd Found Calcd
1a Light brown 168 56 512.8 511.8 68.2 68 4.09 3.71 8.57 8.21 6.56 6.25
1b Yellow brown 155 64 525.3 527.5 65.67 65.97 3.94 3.6 8 7.96 12.29 12.1
1c Yellow brown 155 58 512.8 510.5 68.36 68.16 4.34 3.91 10.59 10.96 6.76 6.26
3a Brown 163 68 571.4 572.5 60.34 60.79 3.48 3.31 7.62 7.33 5.44 5.59
3b Yellow orange 155 64 588.2 588.5 59.35 59.13 3.56 3.22 7.6 7.13 10.71 10.9
3c Yellow brown 156 65 571.4 571.5 60.86 60.89 3.65 3.49 10.19 9.79 5.88 5.59
4a Brown 167 74 540.5 538.5 64.77 64.62 3.74 3.52 10.8 10.39 6 5.94
4b Dark brown 160 56 555.5 554.5 62.97 62.75 2.99 3.42 10.22 10.02 11.67 11.5
4c Brown 164 51 533.3 536.5 64.41 64.74 3.87 3.72 13.28 13 6.03 5.95
5c Dark brown 170 54 540.5 537.5 64.42 64.74 3.86 3.72 13.09 13 6.15 5.95
6a Light Brown 165 65 533.3 536.5 69.56 69.33 4.38 4.65 10.89 10.43 5.96 5.63
6b Brown 163 68 547.9 552.5 67.32 67.33 4.36 4.52 10.17 10.13 11.36 11.6
6c Brown 163 45 533.5 535.5 69.18 69.46 4.42 4.85 12.93 13.07 6.22 5.97
8b Brown 173 63 571.4 569.5 65.5 65.32 4.26 4.21 7 7.37 11.04 11.2
8c Yellow brown 150 56 547.9 552..5 66.98 67.33 4.58 4.52 10.6 10.13 5.37 5.79
9c Brown 158 67 579.7 582.5 64.3 65.92 6.2 6.35 9.4 9.61 5.61 5.49
Table I. Physical Properties and Analyses Data of Compounds
Compoud IR (KBR, CM-1) HNMR (CDCl3, ppm)
1a 1668(C=N), 3428(O-H), 1413(OH,CO), 819(p), 747(C-Cl) 6.98 (Ar-H), 7.38(OH)
1b 1669(C=N), 1359(C-N), 821(P), 748(C-Cl), 2589(S-H) 6.97(Ar-H), 3.79(SH)
1c 1668(C=N), 1357(C-N), 3407, 3473 (N-H), 1225, 1292(C-N,PRI.NH2), 818(P), 747 (C-Cl) 6.95(Ar-H), 5.06(N-H)
3a 1668(C=N), 3440(Br,OH), 1414(OH,CO), 1312(C-N), 816(p), 746(C-Cl) 6.97(Ar-H), 7.39(O-H)
3b 1671(C=N), 1344(C-N), 814(p), 747(C-Cl), 2570(S-H) 7.00(Ar-H), 3.80(S-H)
3c 1625(C=N), 3402(N-H), 1625(N-H), 1250(C-N), 819(p), 753(C-Cl) 7.03(Ar-H), 5.13(N-H)
4a 1626(C=N), 3384(O-H), 1209, 1308(OH,C-O), 808(m), 746(C-Cl) 6.51 (Ar-H), 7.18(N-H)
4b 1625(C=N), 746(m), 746(C-Cl) 7.21(Ar-H), 3.78(S-H)
4c 1671(C=N), 3396(N-H), 1579(N-H), 1263(C=N), 755(ml), 755(C-Cl) 7.26 (Ar-H), 5.10(N-H)
5c 1642(C=N), 3463(N-H), 1578(N-H), 1325(C-N), 848(pl), 776(C-Cl) 7.23 (Ar-H), 5.12(N-H)
6a 1672(C=N), 3422(Br), (O-H), 1235, 1403(OH,CO), 813(P), 748(C-Cl) 6.68(Ar-H), 7.32(O-H)
6b 1663(C=N), 815(P), 745(C-Cl), 2562(S-H) 6.76(Ar-H), 3.82(S-H)
6c 1650(C=N),3447(N-H), 1650, 1580(N-H), 1299(C-N,PRI.NH2), 813(P),747 (C-Cl) 6.68 (Ar-H), 5.05(N-H)
8b 1671(C=N), 748,810(m,p) 748(C-Cl), 2594(S-H) 6.93(Ar-H), 3.96(S-H)
8c 1675(C=N), 3349(N-H), 1570,1675(N-H), 1261, (C-N,PRI.NH2), 751(m), 811 (p), 751(C-Cl) 6.96 (Ar-H), 5.15(N-H)
9c 1672(C=N), 1312(C-N), 3374, 3377(N-H), 1568, 1672(N-H), 1312(C-N), 1749(m), 815(p), 698(C-Cl) 6.99 (Ar-H), 5.15(N-H)
Table II. Spectral Data of Compounds

From Table III, it is evident that compound 4b is highly active against E. faecalis and 8c against E. coli, whereas 4c, 6b, and 6c exhibit excellent results against B. subtilis. Compounds 3b against E. coli and B. subtilis, 4b, 8b, and 9c against E. faecium, 4b against E. coli, and 8c against E. faecium, E. coli, and B. subtilis showed moderate activity. Some compounds showed either mild or no activity. In p-substituted mercapto products inhibition zone order Br<N(CH3)<NO2 against E. faecium and E. faecalis, and NO2<N(CH3)<Br against E. coli and B. subtilis similar and opposite to electronegativity sequence of substituted groups respectively indicated positive effects of electronegativities of substituents of E. faecium and E. faecalis bacteria. P-substituted fluoro compounds 1a and 1c showed good activity against B. subtilis and E. faecium and dimethyl amino compounds against E. faecium, E. coli, and B. subtilis bacteria. The number of methoxy groups corresponded to inhibition in all three bacteria except E. coli. Both p-substituted fluoro compounds showed enhanced activity of the amino group than hydroxy, OH≤NH2, against all four bacteria.

Compound Zone of inhibition (mm)
E Coli B.Subtilis E.Faecium E.Faecalis
1a 10 (0.05) 21 (0.51) 11 (0.05) 10 (0.05)
1c 25 (5.10) 24 (0.51) 29 (0.51) 10 (5.10)
3b 29 (0.06) 27 (0.06) 15 (0.06) 11 (0.06)
4b 10 (0.05) 20 (0.05) 28 (5.50) 34 (0.06)
4c 10 (0.52) 35 (5.37) 11 (0.05) 12 (0.05)
6b 29 (0.52) 34 (0.06) 21 (0.06) 11 (5.52)
6c 10 (0.05) 36 (0.54) 13 (0.05) 11 (0.05)
8b 10 (0.06) 19 (0.06) 27 (0.57) 10 (0.06)
8c 31 (0.55) 20 (0.05) 15 (0.55) 12 (0.55)
9c 10 (0.58) 20 (5.82) 28 (0.58) 13 (0.58)
Control 10 10 10 10
Benzylpenicillin 20 (0.20) 18 (0.20) – 20 (0.20)
Chloramphenicol 14 (0.20) 16 (0.20) – 14 (0.20)
Table III. Antibacterial Activity Of Substituted Pyrimidines

References

  1. Yogesh KG, Vinita G, Sanchita S. Synthesis, characterization and antimicrobial activity of pyrimidine based derivatives. J Pharm Res. 2013;7:491.
     Google Scholar
  2. Brown DJ. The Chemistry of Heterocyclic compounds. Weissberger A; 1962, vol. 16.
     Google Scholar
  3. Zhang N, Ayral- Kaloustian S, Nguyen T, Hernandezb R, Beyerb C. Synthesis and SAR of [1,2,4]Triazolo[1,5-a]pyrimidines, a class of anticancer agents with a unique mechanism of tubulin inhibition. Bioorg Med Lett. 2007;17:3003.
     Google Scholar
  4. Mohamed NR, Talaat El-Saidi MM, Alia YM, Elnagdi MH. Utility of 6-amino-2-thiouracil as a precursor for the synthesis of bioactive pyrimidine derivatives. Bioorg Med Chem. 2007;15:6227.
     Google Scholar
  5. Saif MH, Ashwaq NA, Yasmeen AH, Samir MA, Najah RH. Green synthesis of iron oxide nanorods using Withania coagulans extract improved photocatalytic degradation and antimicrobial activity. Sys Rev Pharm, 2020(11):795806.
     Google Scholar
  6. Wenneng W, Nenjum L, Chenyan W, Qiang F. Synthesis and antifungal activity of pyrimidine derivatives containing an amide moiety. Front Chem. 2021;10:3389.
     Google Scholar
  7. Mohammed A, Hassan Ahmad A. New potential anti-SARS-CoV-2 and anti-cancer therapies of chitosan derivatives and its nanoparticles: preparation and characterization. Arabian J Chem. 2022;15:103846.
     Google Scholar
  8. Suresh M, Sreekanth BJ. Synthesis, antibacterial and antifungal activity of novel benzothiazole pyrimidine derivatives. Arabian J Chem. 2016;9:681–7.
     Google Scholar
  9. Maddila S, Gorle S, Singh M, Lavanya P, Jonnalagadda SB. Synthesis and anti-inflammatory activity of some new 1,3,4-thiadiazoles containing pyrazole and pyrrole nucleus. Lett Drug Des Disc. 2013;10:977–83.
     Google Scholar
  10. Rajendra PY, Srinivasa RA. A study of anti-inflammatory and analgesic activity of new 2,4,6-Trisubstituted pyrimidines. Chem Pharmaceut Bullet. 2011;59:1079–82.
     Google Scholar
  11. Lanier MC, Feher M, Ashweek NJ, Loweth CJ, Reuter JK, Slee DH, et al. Synthesis, characterization and antimicrobial activity of pyrimidine based derivatives. Bioorg Med Chem. 2007;15:5590.
     Google Scholar
  12. Livernton NJ, Bednar RA, Bednar B, Butcher JW, Claiborne CF, Claremon DA. Identification and characterization of 4-Methylbenzyl 4-[(Pyrimidin-2-ylamino)methyl]piperidine-1-carboxylate, an orally bioavailable, brain penetrant NR2B Selective N-Methyl-d-aspartate receptor antagonist. SJ Med Chem. 2007;50:807.
     Google Scholar
  13. Gangjee A, Zeng Y, GuireJJ Mc, Kisluik RL. Synthesis of classical, four-carbon bridged 5-substituted Furo[2,3-d]pyrimidine and 6-Substituted Pyrrolo[2,3-d]pyrimidine analogues as antifolates. J Med Chem. 2005;48:5329.
     Google Scholar
  14. Mallikarjunaswamy C, Othbert P. Studies on synthesis of pyrimidine derivatives and their antimicrobial activity. Arab J Chem. 2017;10:484–90.
     Google Scholar
  15. Dongwei K, Yanying S, Da F, Shenghua G, Zhao W, Lanlan J, et al. Development of novel dihydrofuro[3,4d]pyrimidine derivatives as HIV-1 NNRTIs to overcome the highly resistant mutant strains F227L/V106A and K103N/Y181C. J Med Chem. 2022;65:2458–70.
     Google Scholar
  16. Bruno O, Brullo C, Schenone S, Bondavalli F, Ranise A, Tognolini M, et al. Synthesis, antiplatelet and antithrombotic activities of new 2-substituted benzopyrano[4,3-d]pyrimidin-4-cycloamines and 4-amino/cycloamino-benzopyrano[4,3-d]pyrimidin-5-ones. Med Chem. 2006;14:121.
     Google Scholar
  17. Katiyar SB, Bansal I, Saxena JK, Chauhan PMS. Syntheses of 2,4,6-trisubstituted pyrimidine derivatives as a new class of antifilarial topoisomerase II inhibitors. Bio Org Med Chem Lett. 2005;15:47.
     Google Scholar
  18. Thumm O, Sandoz JB. Angew Chem Internat. 1962;1(11):568–72.
     Google Scholar
  19. Morita Y, Suzuki S, Fukui K, Nakazawa S, Sato K, Shiomi D, et al. A synthetic study of metal complexes of coordinated neutral radicals based on an azaphenalenyl system. Polyhedron. 2003;22:2215–8.
     Google Scholar
  20. Upadhyay RK, Megha, Jain S. Synthesis and antimicrobial activity of 1-[2-(10-p-Chlorobenzyl) phenothiazinyl]-3-(substituted aryl)-2-propen-1-ones. e-J Chem. 2009;S6:S254–8.
     Google Scholar
  21. Megha. Ph.D Thesis, C.C.S University Meerut; 2008.
     Google Scholar