Hys V. Synthesis of fused 1,2,4-thiadiazepines and 1,2-thiazepines based on alkyl sulfonamides

Many sulfonamide derivatives, including cyclic (sultams), are known to exhibit biological activity, making them important building blocks in many researches. They are also widely represented in the composition of medicines. This is due to the structural features of the sulfonamide (–SO2N–) fragment, which is resistant to hydrolysis in a wide range of pH and enzyme action, compared to its bioisostere amide fragment (–СОN–) [1], [2]. At the same time, sulfonamides retain all the positive properties of amides. Sultams have already proven themselves in clinical practice as non-steroidal anti-inflammatory drugs [3], anticonvulsants [4], β1-adrenergic blockers, diuretics [5] and others. It is important to note their use in agriculture as pesticides [6], [7]. Wide application and their big role in organic and asymmetric synthesis [8]–[11] are quite important. Due to the significant role of sultams, numerous ways of synthesis of various bicyclic, tricyclic, tetracyclic and similar systems have been developed. For these goals, the entire synthetic arsenal was used, including reactions of sulfonylation, alkylation, arylation, oxidation, pericyclic reactions, such as Diels-Alder reaction, cross-coupling reactions and others. Despite of the tremendous work have been done in this field, the development of new methods for obtaining cyclic sulfonamides and their further functionalization is one of the important directions of modern organic chemistry and it arouses the interest of many researchers.