Background
Siegmund Gabriel was born on November 7, 1851, in Berlin, Germany. He was the son of Aron and Golde Pollnow Gabriel.
Unter den Linden 6, 10117 Berlin, Germany
Deciding on chemistry as a career, Gabriel enrolled at the University of Berlin and attended lectures in organic chemistry by August Wilhelm von Hofmann and in inorganic chemistry by E. A. Schneider for two semesters beginning in 1871.
Grabengasse 1, 69117 Heidelberg, Germany
At Heidelberg in the spring of 1872 Gabriel studied under Robert Wilhelm Bunsen. A year of military service interrupted his studies, but he returned to Heidelberg in the autumn of 1873 and passed his doctoral examinations summa cum laude in 1874.
Germany
Siegmund Gabriel
Unter den Linden 6, 10117 Berlin, Germany
Deciding on chemistry as a career, Gabriel enrolled at the University of Berlin and attended lectures in organic chemistry by August Wilhelm von Hofmann and in inorganic chemistry by E. A. Schneider for two semesters beginning in 1871.
Grabengasse 1, 69117 Heidelberg, Germany
At Heidelberg in the spring of 1872 Gabriel studied under Robert Wilhelm Bunsen. A year of military service interrupted his studies, but he returned to Heidelberg in the autumn of 1873 and passed his doctoral examinations summa cum laude in 1874.
Germany
Siegmund Gabriel
Siegmund Gabriel was born on November 7, 1851, in Berlin, Germany. He was the son of Aron and Golde Pollnow Gabriel.
During his last year of secondary school, Siegmund developed an interest in science. Deciding on chemistry as a career, Gabriel enrolled at the University of Berlin and attended lectures in organic chemistry by August Wilhelm von Hofmann and in inorganic chemistry by E. A. Schneider for two semesters beginning in 1871.
At Heidelberg in the spring of 1872, Gabriel studied under Robert Wilhelm Bunsen. A year of military service interrupted his studies, but he returned to Heidelberg in the autumn of 1873 and passed his doctoral examinations summa cum laude in 1874. Gabriel received the degree without writing a dissertation since at that time Bunsen did not customarily require it.
Returning to the University of Berlin, where he spent his entire career, Gabriel assisted Hofmann in the inorganic section of the university laboratory. Since his own interests coincided with those of Hofmann, Gabriel spent his years as an assistant on problems in organic chemistry and subsequently devoted his life to that branch of chemistry.
In 1886 Gabriel was appointed a professor of chemistry at Berlin. When Hofmann died in 1892, Emil Fischer, then at Wuerzburg, was chosen to succeed him. Fischer and Gabriel became great friends, and in the dedication of his book Aus meinem Leben Fischer praised Gabriel for his scientific capability, his technical knowledge, and his absolute reliability.
Gabriel’s first research at Berlin, begun in 1876, was on the halogénation of aromatic azo compounds, and in the following year he began a collaboration with the American chemist Arthur Michael on the condensation products of phthalic anhydride. As a result of this work, Gabriel elucidated the structure of phthalylacetic acid in 1884 and in 1886 first synthesized isoquinoline, which had been discovered in coal tar in 1885 by Sebastian Hoogewerff and W. A. van Dorp, who also established its constitution. From this time on, his research was concerned almost exclusively with the heterocyclic compounds of nitrogen.
One of Gabriel’s most significant contributions to organic chemistry was made in 1887, when he announced the important general method for synthesizing pure primary amines, involving the reaction of potassium phthalimide with an alkyl halide, followed by hydrolysis. This reaction, called the Gabriel synthesis, was adapted by Gabriel in 1889 to a procedure for the preparation of amino acids.
In 1891 Gabriel synthesized pyrrolidine from l-amino-4-chlorobutane, and in 1892, using the same procedure, he prepared piperidine from 1-amino- 5-chloropentane. From these heterocyclic rings containing one nitrogen atom, Gabriel turned to a thorough investigation of the diazines. He was the first to prepare phthalazine in 1893 and, with his student James Colman, pyrimidine in 1899. In 1900 he devised a simpler method for obtaining pyrimidine using barbituric acid, and in 1903 he first prepared quinazoline. Gabriel also investigated oxazole, thiazole, and their derivatives. He retired from his professorship of organic chemistry at Berlin in 1921.
Gabriel was a member of the German Academy of Sciences Leopoldina.
In 1883 Gabriel married Anna Fraenkel. They had two sons, both of whom chose medical careers.