Recent data on classical and modified methods for the synthesis of quinoline systems by the Skraup andDoebner-Miller reactions, not included in reviews on heterocycles, are discussed.The need for compounds containing a quinoline fragment in various regions of human activity has increased in recent times. The great attention paid by researchers to the study of quinoline derivatives is explained by the fact that these compounds exhibit a broad range of antimicrobial activity [1-4] and, particularly, antitubercular activity [5] and antimalarial activity [6,7] and are also present in antiallergic and antiasthmatic agents [8]. Classical methods are widely used for their synthesis, and two of these are discussed in the present review.The most important way of constructing the quinoline system involves the cyclization of a substituent in the side chain of a benzene ring. This applies to the synthesis of quinolines by the Skraup and Doebner-Miller reactions. In the classical form, however, these syntheses take place under fairly harsh conditions, and this reduces their preparative value. In recent years, however, the efforts of synthetic chemists have been directed toward modification of these methods. Both traditional and modified approaches to the synthesis are discussed in this review.The first report on the synthesis of quinoline, realized by passing the vapor of ethylaniline and other alkylanilines over heated lead oxide, was published by Koenigs in 1879; in another method (1880) quinoline was obtained by heating the product from the addition of acrolein to aniline. Soon after this Skraup (1880) [9] and Doebner and Miller (1881) put forward their methods [10]; both these syntheses are close to Koenigs' acrolein method and have found widespread application. THE SKRAUP AND DOEBNER-MILLER REACTIONS (THE TRADITIONAL APPROACH)The construction of the quinoline system by the Skraup and Doebner-Miller methods is based on the reaction of an aromatic amine containing at least one free ortho position with a reagent providing a source of the three-carbon fragment.In the classical Skraup method the aromatic amine is heated with glycerol (1), sulfuric acid (which catalyzes the dehydration of glycerol to acrolein (2)), and an oxidizing agent 7, transforming the initially formed 1,2-dihydroquinoline (6) into the fully aromatized heterocycle 8. In the simplest case, with aniline (3) as amine and nitrobenzene (7) as oxidizing agent, the reaction is represented by the following scheme [11]. __________________________________________________________________________________________

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Introduction. The problem of antibiotic resistance of microorganisms is becoming more urgent in the twenty-first century. Microorganisms possess an evolutionary adaptive capacity. Non-adherence to the basic principles of rational antibiotic therapy leads to menacing consequences. More and more pathogenic microbes are becoming resistant to two or more antibiotics. The search for new compounds with antimicrobial activity is one of the principles for overcoming the antibiotic resistance of microorganisms. Materials and methods. Eighteen test-strains of microorganisms and more than 2000 clinical strains of microorganisms, representating the families Micrococcaceae, Streptococcaceae, Enterobacteriaceae, Moraxellaceae, Pseudomonadaceae, Sphingomonadaceae, Xanthomonadaceae were studied for sensitivity to the compounds derived from 4-, 5-, 6- and 7-aminoindoles. A method of serial dilutions to determine the minimal inhibitory concentration (MIC) of the compounds under study was used in the study, as well as a disc diffusion method. Results and discussion. Sensitivity of the test-strains and of clinical strains of microorganisms to the resulting compounds was studied. The compounds based on substituted 4-, 5-, 6-, 7-aminoindoles showed different activity against the test strains and experimental strains of microorganisms in vitro. It was found that the marked antibacterial activity was exhibited by the compounds containing a trifluoromethyl group. The most significant activity was noted in amides and pyrroloquinolones based on 4-aminoindole, 6-aminoindole and 7-aminoindole.The most effective compounds with laboratory codes 5D, 7D, 39D, S3, HD, 4D showed a pronounced antibacterial activity. Conclusion. Antimicrobial activity of the substituted amides and pyrroloquinolines on the basis of 4-, 5-, 6-, 7-aminoindoles was etermined in our study, as well as the spectra of their action against Gram-positive and Gram-negative microorganisms, which are causative agents of non-specific and certain specific human infectious diseases. Moreover, we evaluated the synthetic potentials of the substituted 4-, 5-, 6-, 7-aminoindoles as the starting compounds for synthesizing a series of indolylamides and pyrroloquinolines. Also, the prospects for targeted synthesis of biologically active compounds based on indole-type aromatic amines were determined.