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Picolinic acid is a bidentate chelating agent of elements such as chromium, zinc, manganese, copper, iron, and molybdenum in the human body. [5] [6] It is a substrate in the Mitsunobu reaction. In the Hammick reaction, picolinic acid reacts with ketones to give pyridine-2-carbonols: [7] NC 5 H 4 CO 2 H + R 2 C=O → NC 5 H 4 CR 2 (OH) + CO 2
A pyridinecarboxylic acid is any member of a group of organic compounds which are monocarboxylic derivatives of pyridine. Pyridinecarboxylic acid comes in three isomers: Picolinic acid (2-pyridinecarboxylic acid) Nicotinic acid (3-pyridinecarboxylic acid), also known as Niacin; Isonicotinic acid (4-pyridinecarboxylic acid)
Upon heating α-picolinic acid will spontaneously decarboxylate forming the so-called 'Hammick Intermediate' (3).This was initially thought to be an aromatic ylide, but is now believed to be a carbene [5] [6] In the presence of a strong electrophile, such as an aldehyde or ketone, this species will undergo nucleophilic attack faster than proton transfer.
Isonicotinic acid or pyridine-4-carboxylic acid is an organic compound with the formula C 5 H 4 N(CO 2 H). It is a derivative of pyridine with a carboxylic acid substituent at the 4-position. It is an isomer of picolinic acid and nicotinic acid, which have the carboxyl group at the 2- and 3-position respectively compared to the 4-position for ...
In computational biology, protein pK a calculations are used to estimate the pK a values of amino acids as they exist within proteins.These calculations complement the pK a values reported for amino acids in their free state, and are used frequently within the fields of molecular modeling, structural bioinformatics, and computational biology.
He recognized the acid from β–picoline as Nicotinsäure (nicotinic acid or "niacin"), [12] which Weidel had discovered in 1873. [13] When Weidel decarboxylated the carboxylic acid of each isomer – by dry distilling its calcium salt with calcium oxide – the reaction yielded pyridine, thus showing that picoline was a mixture of three ...
Fluoroantimonic acid is a mixture of hydrogen fluoride and antimony pentafluoride, containing various cations and anions (the simplest being H 2 F + and Sb F − 6).This mixture is a superacid that, in terms of corrosiveness, is trillions of times stronger than pure sulfuric acid when measured by its Hammett acidity function.
If the pH is known, the ratio may be calculated. This ratio is independent of the analytical concentration of the acid. In water, measurable pK a values range from about −2 for a strong acid to about 12 for a very weak acid (or strong base). A buffer solution of a desired pH can be prepared as a mixture of a weak acid and its conjugate base ...