195740-23-9 2-((4-Chloro-2-nitrophenyl)azo)-N-(4-methoxyphenyl)-3-oxobutyramide 23739-66-4 Butanamide, 2-((4-chloro-2-nitrophenyl)azo)-N-(4-methoxyphenyl)-3-oxo- EINECS 245-856-8