ro4938581 ro4938581 ro4938581 is a nootropic drug invented in 2009 by a team working for hoffmann-la roche, which acts as a subtype-selective inverse agonist at the α5 subtype of the benzodiazepine binding site on the gabaa receptor. it has good selectivity for the α5 subtype and did not produce convulsant or anxiogenic effects in animal studies, making it a promising potential nootropic. ro4938581 and a related derivative basmisanil (rg-1662, ro5186582) have subsequently been investigated for the alleviation of cognitive dysfunction in down syndrome. ro4938581identifiers iupac name 3-bromo-10-(difluoromethyl)-9h-benzoimidazotriazolodiazepine cas number883093-10-5 ypubchem cid11624499iuphar/bps4299chemspider9799246uniizk5na2m82jchemblchembl1080588chemical and physical dataformulac13h8brf2n5molar mass352.143 g·mol−13d model (jsmol)interactive image smiles fc(f)c(n=c1)=c(n1c2=c3c=c(br)c=c2)cn4c3=nc=n4 inchi inchi=1s/c13h8brf2n5/c14-7-1-2-9-8(3-7)13-17-5-19-21(13)4-10-11(12(15)16)18-6-20(9)10/h1-3,5-6,12h,4h2key:afjrypjikhmngl-uhfffaoysa-n