Beckmann, Ernst

BECKMANN, ERNST (1853-1923). Beckmann was a German chemist who discovered in 1886 the arrangement of oximes of ketones into acid amides or anilides, named the Beckmann molecular transformation. He was the inventor of two pieces of apparatus used in determining freezing and boiling points of solutions. The Beckmann thermometer is used for determining molecular weights in solutions. 

Beckmann, E. Chem. Ber. 1886, 89, 988. Ernst Otto Beckmann (1853—1923) was bom in Solingen, Germany. He studied chemistry and pharmacy at Leipzig. In addition to the Beckmann rearrangement of oximes to amides, his name is associated with the Beckmann thermometer, used to measure freezing and hoihng point depressions. Mazur, R. H. J. Org. Chem. 1961,26, 1289. 

Beckmann rearrangement The chemical conversion of a ketone oxime into an amide, usually using sulphuric acid as a catalyst. The reaction, used in the manufacture of nylon and other polyamides, is named after the German chemist Ernst Beckmarm (1853-1923). 

Beckmann thermometer A type of mercury thermometer designed to measure small differences in temperature rather than scale degrees. Beckmann thermometers have a larger bulb than common thermometers and a stem with a small internal diameter, so that a range of 5°C covers about 30 centimeters in the stem. The mercury bulb is connected to the stem in such a way that the bulk of the mercury can be separated from the stem once a particular 5° range has been attained. The thermometer can thus be set for any particular range. It is named for the German chemist Ernst Beckmann (1853-1923). 

An important molecular rearrangement of oximes to amides discovered by Ernst Otto Beckmann in 1886 and so named in his honor. The modem version uses one of the most powerful add reagents used in organic chemistry, triflic acid. 

Fresenius, passing his pharmacy examination in 1877. He then joined Kolbe, and his assistant, Ernst von Meyer, and started work on the oxidation of dialkyl sulfides. For this research Beckmann received his PhD in July 1878. Beckmann tried to apply an already-known reaction to discriminate between aldehydes and ketones. This reaction involved the use of hydroxylamine to convert benzophenone into an oxime. Treating this oxime with phosphorus pentachloride he converted it into a substance already characterized by Wallach. This reaction is now known as the Beckmann rearrangement. 

Beckmann rearrangement A type of reaction in which the OXIME of a ketone is converted into an amide using a sulfuric acid catalyst. First discovered by the German chemist Ernst Beckmann (1853-1923), it is used in the manufacture of polyamides see nylon). 

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