Secondary and tertiary sulfonamides: a patent review (2008-2012)

Introduction: Secondary and tertiary sulfonamides (R-SO2NR1R2) are defined by the single or double N-alkyl or N-aryl/heteroaryl substitution of the primary sulfonamide respectively. They can be obtained easily by the classical S(N)2 or nucleophile acyl substitution displacements using the appropriate synthones. Many classes of compounds used in therapy present the substituted sulfonamide groups and there is also a continuous interest in different fields such as the herbicides herein schematically reported. Areas covered: The intent of this article is to give a comprehensive overview of the most important patents in the last decade related to pathologies of great interest. All selected patents claim new compounds bearing the secondary or/and tertiary sulfonamide moiety, and state to have biological activities. The article is neither intended for detailed discussions of the sulfonamides mode of action on the specific therapeutic targets, nor for their contribution to the physicochemical properties of the molecules they are introduced into, as the scientific literature in such topics is exhaustive and in many cases, debates are still ongoing. The main fields covered are related to pathologies affecting the CNS, cardiac disorders, anti-virals, inflammation diseases, glaucoma, bone remodeling, anti-cancer, and finally a section is also dedicated to herbicides. Expert opinion: The insertion of the secondary/tertiary sulfonamide group into the organic scaffolds is chemically straightforward and not associated to particular toxicity in the cells or in the organisms. Therefore, it is possible to create large libraries of compounds, which can be tested for different diseases. As demonstrated by the patents reported in the present review, the research in medicinal chemistry, and other fields, takes big advantages as new leads are created, and might be further developed.