3-(4-Carboxyphenyl)sydnone 3-(p-Carboxyphenyl)sydnone 4-27-00-07444 (Beilstein Handbook Reference) 7614-53-1 BRN 3679419 N-(p-Carboxyphenyl)sydnone N-(p-Karboxyphenyl)-sydnon [German] NSC 63255 Sydnone, 3-(4-carboxyphenyl)- (9CI) Sydnone, 3-(p-carboxyphenyl)-