sb-204741 sb-204741 sb-204741 is a drug which acts as a potent and selective antagonist at the serotonin 5-ht2b receptor, with around 135x selectivity over the closely related 5-ht2c receptor, and even higher over the 5-ht2a receptor and other targets. it is used in scientific research for investigating the functions of the 5-ht2b receptor. sb-204741clinical dataother namessb-204,741identifiers iupac name n-(1-methyl-1h-indol-5-yl)-n'-(3-methylisothiazol-5-yl)urea cas number152239-46-8 ypubchem cid3277600iuphar/bps221chemspider2526822unii9vhm49ms42chebichebi:140936comptox dashboard (epa)dtxsid80390956 echa infocard100.150.276 chemical and physical dataformulac14h14n4osmolar mass286.35 g·mol−13d model (jsmol)interactive image smiles c2c(c)nsc2nc(=o)nc3ccc1n(c)ccc1c3 inchi inchi=1s/c14h14n4os/c1-9-7-13(20-17-9)16-14(19)15-11-3-4-12-10(8-11)5-6-18(12)2/h3-8h,1-2h3,(h2,15,16,19)key:usfufhfqwxdvmh-uhfffaoysa-n (verify)