Optical Spectral Analysis of 4-Aminobenzenesulfonamide through Azo Coupling Reaction and its Commercial Chemical Applications

Alaa Abdulnabi  Ahmed; Maha A. Mohammed

doi:10.30526/39.4.4479

Authors

Alaa Abdulnabi Ahmed Department of Chemistry, College of Education for Pure Science (Ibn Al-Haitham), University of Baghdad, Baghdad, Iraq https://orcid.org/0009-0004-0469-4457
Maha A. Mohammed Department of Chemistry, College of Education for Pure Science (Ibn Al-Haitham), University of Baghdad, Baghdad, Iraq https://orcid.org/0000-0002-4565-8135

DOI:

https://doi.org/10.30526/39.4.4479

Keywords:

4-Aminobenzenesulfonamide, Central composite design, Diazotization, Quercetin, Response surface design

Abstract

Determination of 4-aminobenzenesulfonamide (SFA) by azo-coupling with quercetin, producing a dark yellow color. The method is based on an azo-coupling reaction between SFA and quercetin. The SFA is first diazotized using hydrochloric acid and sodium nitrite at 0–5 °C, then coupled in an alkaline medium. The resulting dark yellow, water-soluble product exhibits a maximum absorbance at 413 nm. The experimental conditions were initially optimized using a univariate approach (OVAT) by examining the effects of individual variables. For further improvement, a central composite design was used to characterize system behavior and identify optimal conditions across multiple variables. The method demonstrated good linearity, with Beer’s law obeyed over the concentration range of 1–10 μg.mL^-1. The detection limit was 1.12 μg.mL-1. The molar absorptivity and Sandell’s sensitivity were 2.53×10⁴ L.mol⁻¹.cm⁻¹ and 6.82×10⁻³ μg.cm^-2, respectively. The resulting color remained stable for more than one hour. The proposed method was successfully applied to sulfadiazine pharmaceutical formulations

Author Biographies

Alaa Abdulnabi Ahmed, Department of Chemistry, College of Education for Pure Science (Ibn Al-Haitham), University of Baghdad, Baghdad, Iraq

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Maha A. Mohammed, Department of Chemistry, College of Education for Pure Science (Ibn Al-Haitham), University of Baghdad, Baghdad, Iraq

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References

1. Tacic A, Nikolic V, Nikolic L, Savic I. Antimicrobial sulfonamide drugs. Advanced Technologies. 2017;6(1):58-71. https://doi.org/10.5937/savteh1701058T.

2. Bisharat H, Ahmad Z, Ahsan I, Haq Z, Azam T, Ahmad F. The evolving role of sulfonamides in medicine and compound development: A Brief Review. Adv J Chem B: Nat Prod Med Chem. 2025;7(2): 130-150. https://doi.org/10.48309/ajcb.2025.506407.1290.

3. Paalaplara K, Chinnagiri K, Chinnagiri R, Pushpavathi I. Synthesis, spectroscopic characterization, computational and electrochemical studies of sulfamethazine based azo dyes. Results Chem. 2025;15: 102238. https://doi.org/10.1016/j.rechem.2025.102238.

4. Caviedes Rubio DI, Buendía-Atencio C, Cardenas-Torres RE, Ortiz CP, Martinez F, Delgado DR. Solubility of sulfamethazine in acetonitrile–ethanol cosolvent mixtures: thermodynamic analysis and mathematical modeling. Molecules 2025;30(17):3590. https://doi.org/10.3390/molecules30173590.

5. Kodide K, Asadi P, Thati J. Solubility and thermodynamic modeling of sulfanilamide in 12 mono solvents and 4 binary solvent mixtures from 278.15 to 318.15 K. J Chem Eng Data. 2019;64(12):5196–5209. https://doi.org/10.1021/acs.jced.9b00411.

6. Cairns D. Essentials of pharmaceutical chemistry. Pharmaceutical Press; 2012, 4th ed.

7. Boo HJ, Yoon D, Choi Y, Kim Y, Cha JS, Yoo J. Quercetin: Molecular insights into its biological roles. Biomolecule. 2025; 15(3):313. https://doi.org/10.3390/biom15030313.

8. Kesharwani SS, Sayre CL, Kesharwani S, Burrows A. Quercetin-Eudragit® polymer complexes with enhanced loading, solubility, stability, and site-specific targeting. There Deliv. 2025;16(7):651–660. https://doi.org/10.1080/20415990.2025.2510889.

9. Turumtay H, Hassan JA, Kazaz S, Gao Y, Tian Y, Chen YC, Kakumanu R, Turumtay EA, Cetiz MV, Choudhary H, Baidoo EEK, Simmons BA, Scheller HV, Lewis JD, Eudes A. Engineered production of hydroxycinnamoyl tyramine conjugates limits the growth of the pathogen pseudomonas syringae in arabidopsis. Plant Cell Environ. 2026;49(5):2516–2530. https://doi.org/10.1111/pce.70403.

10. Song X, Wang Y, Gao L. Mechanism of antioxidant properties of quercetin and quercetin-DNA complex. J Mol Model. 2020;26(6):133. https://doi.org/10.1007/s00894-020-04356-x.

11. Lewandowska H, Świsłocka R, Priebe W, Lewandowski W, Orzechowska S. Towards the development of effective antioxidants the molecular structure and properties part 2. Molecules. 2026; 31(4):720. https://doi.org/10.3390/molecules31040720.

12. Wu L, LeiZJia M, Recent advances in selectivity control for the catalytic reduction of functionalized nitroarenes over metal-based catalysts. Dalton Trans. 2026;17(55):2743-2765. https://doi.org/10.1039/D5DT02581H.

13. Nagaraja P, Naik SD, Shrestha AK, Shivakumar A. A sensitive spectrophotometric method for the determination of sulfonamides in pharmaceutical preparations. Acta Pharm. 2007;57(3):333–342. https://doi.org/10.2478/v10007-007-0026-4.

14. Galil MSA, Abdulalem FR, Mohammed SO, Al-qubati M, Abdallah HM. Advancements in azo-based spectrophotometric techniques for pharmaceutical and environmental analysis via diazotization-coupling reactions. Discov Chem. 2026;3(1):107. https://doi.org/10.1007/s44371-026-00513-y.

15. Belowar S, Jalil MA. Recent advancements in the chemistry of 1, 3, 4-Thiadiazole ring-containing azo dyes. Next Mater. 2026;11:101794. https://doi.org/10.1016/j.nxmate.2026.101794.

16. Zhao M-Y, Tang Y-F, Han G-Z. Recent advances in the synthesis of aromatic azo compounds. Molecules. 2023;28(18):6741. https://doi.org/10.3390/molecules28186741.

17. Khazaa FA, Mohammed FF, Al-Hammashi F. Determination of Quercetin concentration using spectrophotometric method based on diazotization coupling reaction. DJMS. 2025;2(2):58-66. https://doi.org/10.65204/DJMS-D-QC.

18. Qassim. Novel approach of oxidative coupling reaction with 1-naphthol of the simultaneous metformin drug determination in either pharmaceutics formulations or environmental samples of water using homemade CFIA-merging zones techniques. IHJPAS. 2017;30(2):54–68.

19. Ahmed AA, Mohammed MA. UV–Visible spectrophotometric determination of metoclopramide using quercetin in pure and pharmaceutical forms. AMECJ. 2026;9(1):131-144. https://doi.org/10.24200/amecj.v9.i01.1113.

20. Aldandani M, Jan A. Response surface methodology and sensitivity analysis of RP fluid model over curved stretching sheet: non-similar investigation. Case Stud Therm Eng. 2025;68:105884. https://doi.org/10.1016/j.csite.2025.105884.

21. Somadasan S, Subramaniyan G, Athisayaraj MS, Sukumaran SK. Central composite design: An optimization tool for developing pharmaceutical formulations. J Young Pharm. 2024;16(3):400-409. https://doi.org/10.5530/jyp.2024.16.52.