4-(Acetylamino)benzoic Acid-d4; 4-Acetamidobenzoic Acid-d7; 4'-Carboxyacetanilide-d4; N-Acetyl-p-aminobenzoic Acid-d4; NSC 4002-d7; p-(Acetoamino)benzoic Acid-d4; p-(Acetylamino)benzoic Acid-d7; p-Acetamidobenzoic Acid-d4; p-Acetaminobenzoic Acid-d7,Acedoben Stable Isotopes