The nitro-sugars are in reality nitrate-esters, and are closely allied to nitroglycerin and other members of this class. They were first prepared, along with other organic nitrates, by Schonbein1 (1845), then by Sobrero2 (1847) and Flores Demonte and Minard3 (1847). The whole class of bodies obtained by these observers was made by simple nitration, and this led to the name "nitro" being given to them. Subsequently another class of substances possessing entirely different physical and chemical properties was obtained, and, on reduction, yielded amido compounds. To these the name of nitro-compounds has been restricted. It was shown later that nitroglycerin did not yield an amido compound and, therefore, it could not be a true nitro body. It is in fact a nitrate.
The differences may be expressed, taking the derivatives of etham as examples, thus:
C2H5—NO2 C2H5—ONO C
AMARSHALL CR. THE PHARMACOLOGY OF THE NITRO-SUGARS.. JAMA. 1901;XXXVI(18):1241-1242. doi:10.1001/jama.1901.52470180023001f