2-Chloro-1-(3,4-difluoro-phenyl)-ethanone , its cas register number is 51336-95-9. It also can be called alpha-Chloro-3',4'-difluoroacetophenone ; Ethanone, 2-chloro-1-(3,4difluorophenyl)- ; and 3,4-Difluorophenacyl chloride .