Saccharin is a well-known scaffold in drug discovery. Herein, we report the synthesis and preclinical property comparisons of three bioisosteres of saccharin: aza-pseudosaccharins (cluster B), and two new types of aza-saccharins (clusters C and D). We demonstrate a convenient protocol to selectively synthesize products in cluster C or D when primary amines are used. Preclinical characterization of selected matched-pair products is reported. Through comparison of two diastereomers, we highlight how stereochemistry affects the preclinical properties. Given that saccharin-based derivatives are widely used in many chemistry fields, we foresee that structures exemplified by clusters C and D offer new opportunities for novel drug design, creating a chiral center on the sulfur atom and the option of substitution at two different nitrogens.
Keywords: Chemoselectivity; Chlorinating reagent; Functionalization; Medicinal chemistry; N-Substitution; Pseudosaccharin; Regioselectivity; Ring-closure; Sulfonamide; Sulfonimidamide; Telescoping synthesis.