Dimethylsulfonium analogs of the muscarinic agent McN-A-343: [4-[[N-(3- or 4-halophenyl)carbamoyl]oxy]-2-butynyl]dimethylsulfonium perchlorates
摘要:
Some 3- and 4-bromophenyl and dimethylsulfonium analogues of the muscarinic agent [4-[[N-(3-chlorophenyl)-carbamoyl]oxy]-2-butynyl] trimethylammonium chloride (McN-A-343) (1) were synthesized. The new compounds were assayed for effects on arterial blood pressure in the pithed rat (ganglionic muscarinic activity). The dimethylsulfonium salts (13a-d) appeared to be partial agonists in relation to 1. The 4-bromophenyl-substituted trimethylammonium iodide 10d exceeded 1 in potency by 3-fold. The compounds retained the selectivity for ganglionic muscarinic receptors shown by 1 since they had only weak effects on the guinea pig ileum in vitro.
The base catalyzed cyclization of N-aryl and N-alkyl-O-propargyl carbamates is studied in detail. The effect of various bases and solvents on the efficacy of this cyclization reaction is analyzed and a new base–solvent system (LiOH in DMF) for effective cyclization of these carbamates is reported. A number of differentially substituted O-propargyl carbamates were cyclized to the corresponding 2-oxazolidinones
potent inhibitor of neuraminidases, a hydrolase that is responsible for processing sialylated glycoconjugates, is a promising drug candidate for various infective diseases. The current study demonstrates that the use of an aglycone-focused library of 2-difluoromethylphenyl α-sialosides is an effective technique to find potent and selective mechanism-basedlabeling reagents for neuraminidases. The focused