... hydroxylamine (NH2OH), semicarbazide (NH2NHCONH2) and 2, 4-dinitrophenylhydrazine takes place by the same mechanism described for primary amines to give oximes, semicarbazones, and 2, 4-dinitrophenylhydrazones, ... H2NNH NH2 R R R' O C R' R NH2 C N C C R' H N C O R' Oxime Semicarbazone NO2 NO2 c) O + C R H N H N N H2N NO2 Fig 2, 4-Dinitrophenylhydrazone C R' R R' Synthesis of oximes, semicarbazones, and 2, 4-dinitrophenylhydrazones ... synthesized by using diols rather than alcohols (Fig 6) H O CH2CH3 H R C -H2O O O H R H H H H C R OCH2CH3 H C H R O O O CH2CH3 OCH2CH3 -H H R H C O O CH2CH3 Oxonium ion CH2CH3 C CH2CH3 CH2CH3 Acetal...