1-Aminoethanol is an organic compound with the formula CH3CH(NH2)OH. It is classified as an alkanolamine. Specifically, it is a structural isomer of 2-aminoethanol (ethanolamine). These two compounds differ in the position of the amino group. Since the central carbon atom in 1-aminoethanol has four different substituents, the compound has two stereoisomers. Unlike 2-aminoethanol, which is of considerable importance in commerce, 1-aminoethanol is not encountered as a pure material and is mainly of theoretical interest.
1-Aminoethanol exists in a solution of acetaldehyde and aqueous ammonia.[1]
1-Aminoethanol was first prepared in 1833 by the German chemist Johann Wolfgang Döbereiner; its empirical formula was first determined by the German chemist Justus von Liebig in 1835.[3] The structure of 1-aminoethanol remained unproven until 1877, when the German-Italian chemist Robert Schiff showed that the structure was CH3CH(OH)NH2.[4]
^Liebig, Justus (1835) "Ueber die Producte der Oxydation des Alkohols" (On the products of oxidation of alcohol [i.e., ethanol]), Annalen der Chemie, 14 : 133–167. In 1821, Döbereiner had prepared what he called Saüerstoffäther (literally: ether oxide), which, as Liebig later showed, contained acetaldehyde. On p. 134, Liebig states that Döbereiner first produced 1-amino-ethanol by perfusing acetaldehyde (Saüerstoffäther or Aldehyd, as Liebig called it) with ammonia gas (Ammoniak) : "Der berühmte Entdecker des Acetals theilte mir damals gleichzeitig mit, dass sein Saüerstoffäther mit Ammoniakgas eine weisse krystallinische Verbingdung bilde; ... " (The famous discoverer of acetal [viz, Döbereiner] simultaneously communicated to me at that time that his ether oxide forms a white crystalline compound with ammonia gas; ... ) On p. 146, Liebig presented his empirical formula for 1-aminoethanol: C4H14N2O2. If the subscripts are divided by 2, the resulting formula is correct.
^Although it had long been assumed that the structure of 1-aminoethanol was CH3CH(OH)NH2, it had not been proven that 1-aminoethanol contained a hydroxyl (-OH) group until Schiff's investigation in 1877. See:
