Siegmund Gabriel (7 November 1851 – 22 March 1924) was a German chemist.

Scientific career

Siegmund Gabriel began studying chemistry at the

University of Berlin Humboldt-Universität zu Berlin (german: Humboldt-Universität zu Berlin, abbreviated HU Berlin) is a German public research university in the central borough of Mitte in Berlin. It was established by Frederick William III on the initiative o ...

in 1871. He continued his studies at the

University of Heidelberg } Heidelberg University, officially the Ruprecht Karl University of Heidelberg, (german: Ruprecht-Karls-Universität Heidelberg; la, Universitas Ruperto Carola Heidelbergensis) is a public research university in Heidelberg, Baden-Württemberg, ...

in 1872 with Professor

Robert Wilhelm Bunsen Robert Wilhelm Eberhard Bunsen (; 30 March 1811 – 16 August 1899) was a German chemist. He investigated emission spectra of heated elements, and discovered caesium (in 1860) and rubidium (in 1861) with the physicist Gustav Kirchhoff. The Buns ...

. In 1874, he received his doctorate and then returned to Berlin. He began teaching as an assistant, initially in the inorganic chemistry department, before becoming an associate professor in 1886. Gabriel later turned to

organic chemistry Organic chemistry is a subdiscipline within chemistry involving the scientific study of the structure, properties, and reactions of organic compounds and organic materials, i.e., matter in its various forms that contain carbon atoms.Clayden, J.; ...

in his own research. One of Gabriel’s most significant contributions to organic chemistry was made in 1887, when he discovered the

Gabriel Synthesis The Gabriel synthesis is a chemical reaction that transforms primary alkyl halides into primary amines. Traditionally, the reaction uses potassium phthalimide. The reaction is named after the German chemist Siegmund Gabriel. The Gabriel reaction ...

with his partner James Dornbush. The Gabriel Synthesis is a reaction which synthesizes pure

primary amines In chemistry, amines (, ) are compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are formally derivatives of ammonia (), wherein one or more hydrogen atoms have been replaced by a substituent s ...

, involving the reaction of

potassium phthalimide Potassium phthalimide is a chemical compound of formula C8H4KNO2. It is the potassium salt of phthalimide, and usually presents as fluffy, very pale yellow crystals. It can be prepared by adding a hot solution of phthalimide in ethanol to a soluti ...

with an

alkyl halide The haloalkanes (also known as halogenoalkanes or alkyl halides) are alkanes containing one or more halogen substituents. They are a subset of the general class of halocarbons, although the distinction is not often made. Haloalkanes are widely ...

, followed by

hydrolysis Hydrolysis (; ) is any chemical reaction in which a molecule of water breaks one or more chemical bonds. The term is used broadly for substitution reaction, substitution, elimination reaction, elimination, and solvation reactions in which water ...

. The Gabriel Synthesis was adapted by Gabriel in 1889 to a procedure for the preparation of

amino acid Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although hundreds of amino acids exist in nature, by far the most important are the alpha-amino acids, which comprise proteins. Only 22 alpha am ...

s. In 1891 Gabriel synthesized pyrrolidine from l-amino-4-chlorobutane, and in 1892, using the same procedure, he prepared

piperidine Piperidine is an organic compound with the molecular formula (CH2)5NH. This heterocyclic compound, heterocyclic amine consists of a six-membered ring containing five methylene bridges (–CH2–) and one amine bridge (–NH–). It is a colorless ...

from 1-amino- 5-chloropentane. He was the first to prepare phthalazine in 1893 and, with his student James Colman,

pyrimidine Pyrimidine (; ) is an aromatic, heterocyclic, organic compound similar to pyridine (). One of the three diazines (six-membered heterocyclics with two nitrogen atoms in the ring), it has nitrogen atoms at positions 1 and 3 in the ring. The other ...

in 1899. In 1900, he devised a simpler method for obtaining pyrimidine using barbituric acid, and in 1903 he first prepared

quinazoline Quinazoline is an organic compound with the formula C8H6N2. It is an aromatic heterocycle with a bicyclic structure consisting of two fused six-membered aromatic rings, a benzene ring and a pyrimidine ring. It is a light yellow crystalline solid ...

. Gabriel also investigated

oxazole Oxazole is the parent compound for a vast class of heterocyclic aromatic organic compounds. These are azoles with an oxygen and a nitrogen separated by one carbon. Oxazoles are aromatic compounds but less so than the thiazoles. Oxazole is a weak ...

thiazole Thiazole, or 1,3-thiazole, is a heterocyclic compound that contains both sulfur and nitrogen. The term 'thiazole' also refers to a large family of derivatives. Thiazole itself is a pale yellow liquid with a pyridine-like odor and the molecular for ...

, and their derivatives. Gabriel reported what became the

Robinson–Gabriel Synthesis The Robinson–Gabriel synthesis is an organic reaction in which a 2-acylamino-ketone reacts intramolecularly followed by a dehydration to give an oxazole. A cyclodehydrating agent is needed to catalyze the reaction It is named after Sir Robert Ro ...

in 1910. In 1913, he was appointed full honorary professor at the University of Berlin, a position he retired from in 1921. Gabriel was a member of the

German Chemical Society The German Chemical Society (German: ', GDCh) is a learned society and professional association founded in 1949 to represent the interests of German chemists in local, national and international contexts. GDCh "brings together people working in che ...

and served on its board for many years.

Personal life

Siegmund Gabriel was born on November 7, 1851 in Berlin, the youngest of factory owner Aron Gabriel and his wife Golchen (Golde) née Pollnow's six children. His father owned a trimmings factory in Berlin. On August 28, 1883, he married Anna née Fränkel, who was born on April 26, 1862 in Neustadt in Upper Silesia as the daughter of the entrepreneur Abraham Fränkel and his first wife Friederike née Caro. Siegmund and Anna Gabriel had two sons: Ernst, born in 1885, became a dermatologist and later earned his living as a chicken farmer after his emigration to

Israel Israel (; he, יִשְׂרָאֵל, ; ar, إِسْرَائِيل, ), officially the State of Israel ( he, מְדִינַת יִשְׂרָאֵל, label=none, translit=Medīnat Yīsrāʾēl; ), is a country in Western Asia. It is situated ...

; Kurt, born in 1896, became a dentist and was able to continue to work in this profession after emigrating to

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

. Siegmund Gabriel died in Berlin on March 22, 1924. His widow Anna Gabriel was deported during the holocaust to

Theresienstadt Theresienstadt Ghetto was established by the Schutzstaffel, SS during World War II in the fortress town of Terezín, in the Protectorate of Bohemia and Moravia (German occupation of Czechoslovakia, German-occupied Czechoslovakia). Theresienstad ...

on October 30, 1942. She perished there on April 4, 1943. Original documents from Siegmund Gabriel's estate have been kept at the

Leo Baeck Institute The Leo Baeck Institute, established in 1955, is an international research institute with centres in New York City, London, and Jerusalem that are devoted to the study of the history and culture of German-speaking Jewry. Baeck was its first intern ...

New York New York most commonly refers to: * New York City, the most populous city in the United States, located in the state of New York * New York (state), a state in the northeastern United States New York may also refer to: Film and television * '' ...

since 1979.

References

* 1851 births 1924 deaths German physiologists 19th-century German chemists Scientists from Berlin Humboldt University of Berlin alumni Heidelberg University alumni Humboldt University of Berlin faculty 20th-century German chemists {{Germany-chemist-stub