Synthesis of 2-Naphthyl 2-Chloroacetate and Study of Its Nucleophilic Substitution Reactions with Citric Acid

The article analytically and experimentally presents the possibilities for the synthesis of 2-naphthyl 2-chloroacetate. Particular attention is given to the reaction conditions. Based on the literature review, the selective insecticidal activity and chemical properties of 2-naphthol, as well as the features of its nucleophilic substitution reactions with citric acid, are studied. The aim of the research is to develop an efficient method for the synthesis of O-chloroacetylated naphthol and to investigate the nucleophilic substitution reactions of the O-chloroacetylation product with citric acid. The chloracetylation of 2-naphthol in dichloroethane solution without a catalyst leads exclusively to O-acylation, resulting in the formation of 2-naphthyl 2-chloroacetate with a 95% yield. The composition and structure of the synthesized compounds were confirmed by spectroscopic methods. Since the reaction proceeds in dichloroethane without a catalyst, no acylium cation (ion pair) is formed. Therefore, the reaction follows a nucleophilic substitution mechanism at the carbonyl group of the chloroacetyl chloride molecule, yielding an ester product. The oxygen atom in the naphthol molecule serves as the nucleophilic reagent. The nucleophilic substitution products of 2-naphthyl 2-chloroacetate with citric acid were studied using thin-layer chromatography (TLC), and their composition was confirmed with reference substances. The physical constants of 2-naphthyl 2-chloroacetate were determined, and its composition and structure were verified using TLC, IR, and NMR spectroscopy.