InChI=1/C18H25N2O4PS/c1-5-23-25(22,24-6-2)12-11-16-18(21,13(3)4)20-15-10-8-7-9-14(15)19-17(20)26-16/h7-11,13,21H,5-6,12H2,1-4H3/b16-11 diethyl [(2Z)-2-(3-hydroxy-3-isopropyl[1,3]thiazolo[3,2-a]benzimidazol-2(3H)-ylidene)ethyl]phosphonate phosphonic acid, [(2Z)-2-[3-hydroxy-3-(1-methylethyl)thiazolo[3,2-a]benzimidazol-2(3H)-ylidene]ethyl]-, diethyl ester