Synthesis and structure-activity relationships in a series of ethenesulfonamide derivatives, a novel class of endothelin receptor antagonists

Electrochemical Multicomponent Synthesis of Alkyl Alkenesulfonates using Styrenes, SO2 and Alcohols

A novel electrochemical approach to access alkyl alkenesulfonates via a multicomponent reaction was developed. The metal-free method features easy-to-use SO2 stock solution forming monoalkylsulfites from alcohols with an auxiliary base in-situ. These intermediates serve a dual role as starting materials and as supporting electrolyte enabling conductivity. Anodic oxidation of the substrate styrene, radical addition of these monoalkylsulfites and consecutive second oxidation and deprotonation preserve the double bond and form alkyl β-styrenesulfonates in a highly regio- and stereoselective fashion. The feasibility of this electrosynthetic method is demonstrated in 44 examples with yields up to 81 %, employing various styrenes and related substrates as well as a diverse set of alcohols. A gram-scale experiment underlines the applicability of this process, which uses inexpensive and readily available electrode materials.

Synthesis of a unique isoindoline/tetrahydroisoquinoline-based tricyclic sultam library utilizing a Heck-aza-Michael strategy

The synthesis of a unique isoindoline- and tetrahydroisoquinoline (THIQ)-containing tricyclic sultam library, utilizing a Heck-aza-Michael (HaM) strategy is reported. Both isoindoline and THIQ rings are installed through a Heck reaction on a vinylsulfonamide, followed by one-pot deprotection and intramolecular aza-Michael reaction. Subsequent cyclization with either paraformaldehyde condensation or 1,1'-carbonyldiimidazole coupling generates a variety of tricyclic sultams. Overall, a 160-member library of these sultams, together with their isoindolines/THIQ and secondary sulfonamides precursors, were constructed using this strategy.

Renal protective effect of YM598, a selective endothelin ET(A) receptor antagonist, against diabetic nephropathy in OLETF rats

We have investigated the effect of potassium (E)-N-[6-methoxy-5-(2-methoxyphenoxy)-2-(pyrimidin-2-yl) pyrimidin-4-yl]-2-phenylenthenesulfonamidate (YM598), a selective endothelin ET(A) receptor antagonist, on renal function in Otsuka Long-Evans Tokushima Fatty (OLETF) rats, an animal model of type II diabetes. YM598 (0.1 or 1 mg kg(-1)), enalapril (5 mg kg(-1)), an angiotensin-converting enzyme inhibitor, or vehicle was administered once daily by gastric gavage to 22-week-old male Otsuka Long-Evans Tokushima Fatty rats for 32 weeks. Enalapril but not YM598 mildly lowered blood pressure in the diabetic rats. YM598 blunted the development of albuminuria in a dose-dependent manner. High dose of YM598 reduced albuminuria comparable to enalapril. Urinary endothelin-1 excretion was greater in the diabetic than in the control rats, and was not substantially influenced by the agents. These data suggest that endothelin is involved in the progression of diabetic nephropathy in Otsuka Long-Evans Tokushima Fatty rats, and an endothelin ET(A) receptor antagonist may be useful for the treatment of diabetic nephropathy.