1-oxa-2,7-diazaspiro[4.4]non-2-en-6-one, 3-(4-fluorophenyl)-8,8-dimethyl- 3-(4-fluorophenyl)-8,8-dimethyl-1-oxa-2,7-diazaspiro[4.4]non-2-en-6-one InChI=1/C14H15FN2O2/c1-13(2)8-14(12(18)16-13)7-11(17-19-14)9-3-5-10(15)6-4-9/h3-6H,7-8H2,1-2H3,(H,16,18