2-Picolinic acid

Chemical Properties

Off-white to tan powder. easily soluble in glacial acetic acid, almost insoluble in ether, chloroform and carbon disulfide.

Uses

2-Picolinic acid is used as a chelate for alkaline earth metals. It is also used to prepare picolinato ligated transition metal complexes. In synthetic organic chemistry, has been used as a substrate in the Mitsunobu reaction and in the Hammick reaction.

Definition

ChEBI: Picolinic acid is a pyridinemonocarboxylic acid in which the carboxy group is located at position 2. It is an intermediate in the metabolism of tryptophan. It has a role as a MALDI matrix material and a human metabolite. It is a conjugate acid of a picolinate.

Application

2-Picolinic acid is used in the preparation of 2-Aminodihydro[1,3]thiazines as BACE 2 inhibitors and their preparation and use in the treatment of diabetes.
Metal complexes of picolinic acid were prepared by the refluxion of metal salts and picolinic acid in ethanol taking 1:3 molar ratio for 6 hours. The solutions were concentrated and cooled, to crystallize out the complexes.The complexes were washed with ether to remove the excess ligand.

reaction suitability

reagent type: catalyst
reagent type: ligand
reaction type: C-H Activation

Synthesis

2-Picolinic acid synthesis: In a 500ml three-necked flask, add 100g of 2-cyanopyridine and 200g of deionized water, then start stirring, heat up to 50°C, add 128.2g of 30% sodium hydroxide to the flask, after adding, add Continue to heat up, react under reflux for 4 hours, then distill water, after 50 g of distilled water, cool the reaction solution to 20°C, add 30% hydrochloric acid, adjust the pH value of the reaction solution to 2.5, then turn on the steam to heat up the water and steam to the kettle When the temperature reaches 120°C, the reaction solution is evaporated to dryness, and the distilled water is completed. Then, 300 g of anhydrous alcohol is added dropwise to the flask to maintain the temperature of the reaction solution at 55°C. After cooling and crystallization, a solid was precipitated, filtered and dried to obtain 106.0 g of 2-picolinic acid with a yield of 89.6%.

Purification Methods

Crystallise the acid from water or *benzene. The picrate has m 185-187o (from MeOH). [Beilstein 22 H 33, 22 I 502, 22 II 30, 22 III/IV 303, 22/2 V 3.]