fenobam fenobam fenobam is an imidazole derivative developed by mcneil laboratories in the late 1970s as a novel anxiolytic drug with an at-the-time-unidentified molecular target in the brain. subsequently, it was determined that fenobam acts as a potent and selective negative allosteric modulator of the metabotropic glutamate receptor subtype mglur5, and it has been used as a lead compound for the development of a range of newer mglur5 antagonists. fenobam names preferred iupac name n-(3-chlorophenyl)-n′-(1-methyl-4-oxo-4,5-dihydro-1h-imidazol-2-yl)urea identifiers cas number 57653-26-6 y 3d model (jsmol) interactive image chembl chembl239800 n chemspider 142953 n echa infocard 100.165.052 iuphar/bps 1434 mesh fenobam pubchem cid 162834 unii 078rcy7i27 n comptox dashboard (epa) dtxsid5046770 inchi inchi=1s/c11h11cln4o2/c1-16-6-9(17)14-10(16)15-11(18)13-8-4-2-3-7(12)5-8/h2-5h,6h2,1h3,(h2,13,14,15,17,18) nkey: dwpqodzaoswnhb-uhfffaoysa-n ninchi=1/c11h11cln4o2/c1-16-6-9(17)14-10(16)15-11(18)13-8-4-2-3-7(12)5-8/h2-5h,6h2,1h3,(h2,13,14,15,17,18)key: dwpqodzaoswnhb-uhfffaoyac smiles o=c1cn(c)c(nc(nc2=cc=cc(cl)=c2)=o)=n1 properties chemical formula c11h11cln4o2 molar mass 266.684 except where otherwise noted, data are given for materials in their standard state (at 25 °c , 100 kpa). n verify (what is yn ?) infobox references fenobam has anxiolytic effects comparable to those of benzodiazepine drugs, but was never commercially marketed for the treatment of anxiety due to dose-limiting side effects such as amnesia and psychotomimetic symptoms. following the discovery of its activity as a potent negative allosteric modulator of mglur5, fenobam has been re-investigated for many applications, with its profile of combined antidepressant, anxiolytic, analgesic and anti-addictive effects potentially useful given the common co-morbidity of these symptoms. it has also shown promising initial results in the treatment of fragile x syndrome. it was developed by a team at mcneil laboratories in the 1970s. chemistry fenobam is known to exist in five crystalline forms, all of them exhibiting a tautomeric structure with the proton attached to the five membered ring nitrogen.