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Von Pechmann was born in Nürnberg, the only son of a doctor, who was also named Hans.The von Pechmanns had distinguished themselves as soldiers; in 1702, von Pechmann's ancestor Martin Günther von Pechmann, a general of artillery in the Bavarian army, had been raised to the rank of a baron of the Holy Roman Empire by Leopold I. [6]
in 1899 Hans von Pechmann added diazomethane to ether, and noted the formation of polymethylene, a type of polyethylene, identified in 1900 by Eugen Bamberger and Friedrich Tschirner, but had not realised that it has any commercial significance; ICI in Cheshire in England will, in 1933
1898: Synthesis of polyethylene, the most common plastic, by Hans von Pechmann [159] 1898: First synthesis of purine by Emil Fischer. He had also coined the word in 1884. [160] Early 20th century: Schlenk flask by Wilhelm Schlenk [161] 1900s: Haber process by Carl Bosch and Fritz Haber [133] 1902: Ostwald process by Wilhelm Ostwald [162]
Pechmann condensation and Pechmann pyrazole synthesis. Julius Richard Petri: Bacteriologist who is generally credited with inventing the Petri dish while working as assistant to Robert Koch. Emil Pfeiffer: Discovery of Infectious mononucleosis; Fritz Pfleumer: Inventor of magnetic tape for recording sound. He builts the world's first practical ...
Polyethylene was first synthesized by the German chemist Hans von Pechmann, who prepared it by accident in 1898 while investigating diazomethane. [12] [a] [13] [b] When his colleagues Eugen Bamberger and Friedrich Tschirner characterized the white, waxy substance that he had created, they recognized that it contained long −CH 2 − chains and termed it polymethylene.
Two German chemists also preceded Schlotterbeck in discovery of the reaction, Hans von Pechmann in 1895 and Viktor Meyer in 1905. [4] [5] The reaction has since been extended to the synthesis of β-keto esters from the condensation between aldehydes and diazo esters. [6] The general reaction scheme is as follows: General Scheme for Buchner Reaction
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