methyl 2-(8-fluoro-3-(2-methoxy-5-(trifluoromethyl)phenyl)-2-(4-(3-methoxy-d3-phenyl)piperazin-1-yl)-3,4-dihydroquinazolin-4-yl)acetate,methyl 2-(8-fluoro-3-(2-methoxy-5-(trifluoromethyl)phenyl)-2-(4-(3-methoxy-d3-phenyl)piperazin-1-yl)-3,4-dihydroquinazolin-4-yl)acetate,Letermovir Stable Isotopes