Hans von Pechmann was a German chemist

Chemist

A chemist is a scientist trained in the study of chemistry. Chemists study the composition of matter and its properties such as density and acidity. Chemists carefully describe the properties they study in terms of quantities, with detail on the level of molecules and their component atoms...

, renowned for his discovery of diazomethane

Diazomethane

Diazomethane is the chemical compound CH2N2. It is the simplest of diazo compounds. In the pure form at room temperature, it is a extremely sensitive explosive yellow gas, thus it is almost universally used as a solution in diethyl ether...

 in 1894. , Pechmann condensation

Pechmann condensation

The Pechmann condensation is a synthesis of coumarins, starting from a phenol and a carboxylic acid or ester containing a β-carbonyl group . The condensation is performed under acidic conditions. The mechanism involves an esterification/transesterification followed by attack of the activated...

 and Pechmann pyrazole synthesis. He also first prepared 1,2-diketones (e.g., diacetyl

Diacetyl

Diacetyl is a natural byproduct of fermentation. It is a vicinal diketone with the molecular formula C4H6O2...

), acetonedicarboxylic acid

Acetonedicarboxylic acid

Acetonedicarboxylic acid or 3-oxoglutaric acid is a simple carboxylic acid, which may be used as a building block in organic chemistry....

, methylglyoxal

Methylglyoxal

Methylglyoxal, also called pyruvaldehyde or 2-oxopropanal is the aldehyde form of pyruvic acid. It has two carbonyl groups, so it is a dicarbonyl compound. Methylglyoxal is both an aldehyde and a ketone....

 and diphenyltriketone; established the symmetrical structure of anthraquinone

Anthraquinone

Anthraquinone, also called anthracenedione or dioxoanthracene is an aromatic organic compound with formula . Several isomers are possible, each of which can be viewed as a quinone derivative...

.

Von Pechmann also discovered polyethylene

Polyethylene

Polyethylene or polythene is the most widely used plastic, with an annual production of approximately 80 million metric tons...

 plastics serendipitously in 1898, when accidentally heating diazomethane.

After studying with Heinrich Limpricht

Heinrich Limpricht

Heinrich Limpricht was a German chemist. Limpricht was a pupil of Friedrich Wöhler; he worked on the chemistry of furans and pyrroles, discovering furan in 1870....

 at the University of Greifswald he became Professor at the University of Munich till 1895. He was professor at the University of Tübingen from 1895 till his death in 1902.