Synthesis of new Organic reagent by Vilsmeier – Haack reaction and estimation of pharmaceutical compounds (Mesalazine) containing aromatic amine groups

Document Type : Original Article


1 1Department of Chemistry, College of Education for Girls, University of Mosul, Mosul , Iraq.

2 Dept.of Chemistry, College of Education for girls, Mosul University, Iraq

3 Department of Chemistry, College of Education for pure science, University of Mosul


In this paper Synthesis new heterocyclic compound from p-phenylenediamine by converting p-diacetanilide (1) and reacting with Vilsmeier-Haack reagent to give ( 2,7-dicloropyrido[2,3-g]quinoline-3,8-dicarbaldehyde) (2). The two carbaldehydes in compound (2) react with two moles 1-tetralone to give chalcone(3). This chalcone is used as the reagent to estimate the pharmaceutical compounds containing aromatic amino groups. Where a sensitive spectrophotometric method has been developed for the determination of mesalazine by diazotization and coupling reaction of mesalazine with chalcone reagent in basic medium to form a colored water-soluble and stable azo-dye. The product shows maximum absorption at 450 nm. Beer's law was obeyed over the concentration range 0.5-27.5 µg/ml with molar absorptivity of 9494.37 The limit of detection and quantitation is 0.161and 0.538 µ The recovery was 101.48% with a relative standard deviation ≤ 3.265%. Mesalazine and Chalcone reagent products were formed in the ratio of 2: 1 . Full-color development was described and the proposed method was successfully applied to determine mesalazine in the pharmaceuticals preparation. The proposed method was applied to pharmaceutical preparations containing mesalazine derivatives.


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