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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
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.
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 ...
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)
Most of the reactions of picoline are centered on the methyl group. For example, the principal use of 2-picoline is as a precursor of 2-vinylpyridine. The conversion is achieved by condensation with formaldehyde: The copolymer of 2-vinylpyridine, butadiene and styrene is used as an adhesive for textile tire cord.
Zinc picolinate (or ZnPic) is the zinc coordination complex derived from picolinic acid and zinc(II). It has the formula Zn(NC 5 H 4 CO 2) 2 (H 2 O) 2.The complex adopts an octahedral molecular geometry, containing two bidentate picolinate ligands (conjugate base of picolinic acid) and two aquo ligands.
In the related Hammick reaction, uncatalyzed decarboxylation of a picolinic acid gives a stable carbene that attacks a carbonyl electrophile. Oxidative decarboxylations are generally radical reactions. These include the Kolbe electrolysis and Hunsdiecker-Kochi reactions. The Barton decarboxylation is an unusual radical reductive decarboxylation.
The systematic name of this enzyme class is 2-amino-3-(3-oxoprop-1-en-1-yl)but-2-enedioate carboxy-lyase (2-aminomuconate-semialdehyde-forming). Other names in common use include picolinic acid carboxylase, picolinic acid decarboxylase, alpha-amino-beta-carboxymuconate-epsilon-semialdehade decarboxylase, alpha-amino-beta-carboxymuconate-epsilon-semialdehyde, beta-decarboxylase, 2-amino-3-(3 ...