URB754

URB754 was originally reported by Piomelli et al. to be a potent, noncompetitive inhibitor of monoacylglycerol lipase (MGL).^[1] However, recent studies have shown that URB754 failed to inhibit recombinant MGL, and brain FAAH activity was also resistant to URB754.^[2] In a later study by Piomelli et al., the MGL-inhibitory activity attributed to URB754 is in fact due to a chemical impurity present in the commercial sample, identified as bis(methylthio)mercurane.^[3]

URB754

Names
Preferred IUPAC name 6-Methyl-2-(4-methylanilino)-4H-3,1-benzoxazin-4-one
Identifiers
CAS Number	86672-58-4 Y
3D model (JSmol)	Interactive image
ChemSpider	741376 N
ECHA InfoCard	100.236.075
PubChem CID	848487
UNII	7672NBP7ZF Y
CompTox Dashboard (EPA)	DTXSID10357239
InChI InChI=1S/C16H14N2O2/c1-10-3-6-12(7-4-10)17-16-18-14-8-5-11(2)9-13(14)15(19)20-16/h3-9H,1-2H3,(H,17,18) N Key: GFWNGVKCDGYFKG-UHFFFAOYSA-N N InChI=1/C16H14N2O2/c1-10-3-6-12(7-4-10)17-16-18-14-8-5-11(2)9-13(14)15(19)20-16/h3-9H,1-2H3,(H,17,18) Key: GFWNGVKCDGYFKG-UHFFFAOYAI
SMILES CC1=CC=C(C=C1)NC2=NC3=C(C=C(C=C3)C)C(=O)O2
Properties
Chemical formula	C16H14N2O2
Molar mass	266.300 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

References

1. Makara JK, Mor M, Fegley D, Szabó SI, Kathuria S, Astarita G, Duranti A, Tontini A, Tarzia G, Rivara S, Freund TF, Piomelli D (2005). "Selective inhibition of 2-AG hydrolysis enhances endocannabinoid signaling in hippocampus". Nat. Neurosci. 8 (9): 1139–41. doi:10.1038/nn1521. PMID 16116451. S2CID 52810445.
2. Saario SM, Palomäki V, Lehtonen M, Nevalainen T, Järvinen T, Laitinen JT (2006). "URB754 has no effect on the hydrolysis or signaling capacity of 2-AG in the rat brain". Chem. Biol. 13 (8): 811–4. doi:10.1016/j.chembiol.2006.07.008. PMID 16931330.
3. Tarzia, Giorgio; Antonietti, Francesca; Duranti, Andrea; Tontini, Andrea; Mor, Marco; Rivara, Silvia; Traldi, Pietro; Astarita, Giuseppe; King, Alvin; Clapper, Jason R.; Piomelli, Daniele (2007). "Identification of a Bioactive Impurity in a Commercial Sample of 6-Methyl-2-p-Tolylaminobenzo[d][1,3]Oxazin-4-One (URB754)". Annali di Chimica. 97 (9): 887–94. doi:10.1002/adic.200790073. PMID 17970304.