4-[(4-hydroxyphenyl)amino]-4-oxobutanoic acid 4-[(4-hydroxyphenyl)amino]-4-oxo-butanoic acid 4-[(4-hydroxyphenyl)amino]-4-keto-butyric acid 4-(4-Hydroxyanilino)-4-oxobutanoic acid Butanoic acid, 4-(4-hydroxyphenylamino)-4-oxo- Oprea1_551196