Felix Hoffmann in 1890 with the pharmaceutical state exam. In 1891 he graduated magna cum laude from the University of Munich. Two years later he earned his doctorate, also magna cum laude, after completing his thesis entitled "On certain derivatives of dihydroanthracene". In 1894, he joined Bayer as a research chemist. On 10 August 1897 Hoffmann synthesized acetylsalicylic acid (ASA) while working at Bayer under Arthur Eichengrün. By combining salicylic acid with acetic acid, he succeeded in creating ASA in a chemically pure and stable form. The pharmacologist responsible for verifying these results was skeptical at first, yet once several large-scale studies
Tetrolic acid (water, ethanol) and may be recrystallized from non polar solvents (such as heptane, toluene). The compound is a white crystalline solid which can exist in two polymorphous crystalline forms. The proton nuclear magnetic resonance (H-NMR) spectrum in deuterated dimethyl sulfoxide shows a characteristic singlet peak at 1.99 ppm corresponding to the -CH protons. Tetrolic acid Tetrolic acid (2-butynoic acid) is a short-chain unsaturated carboxylic acid, described by the formula CH-C≡C-COH. Salts and esters of tetrolic acid are known as tetrolates. The first reported synthesis of tetrolic acid is believed to be by German chemist Johann Georg Anton Geuther in 1871