Preparation method of 2-amino-4-methyl-3,5-dibromopyridine_Industrial additives

Background and overview of the preparation method of 2-amino-4-methyl-3,5-dibromopyridine

2-Amino-4-methyl-3,5-dibromopyridine is an organic intermediate, which can be prepared from bromination of 2-amino-4-methylpyridine. PCT Int. Appl., 2000021963 reported that 2-amino-4-methyl-3,5-dibromopyridine can be used to prepare IL-8 receptor antagonists. The compounds as IL-8 receptor antagonists are compatible with IL-8 receptor antagonists. 8 production (which is responsible for chemotaxis of neutrophils and T-cell subtypes to sites of inflammation) is beneficial in diseases associated with increased production.

Preparation method of 2-amino-4-methyl-3,5-dibromopyridine

Brome (1.9 mL, 37.0 mmol) was added dropwise to a slurry of 2-amino-4-methylpyridine (4.00 g, 37.0 mmol) in fuming sulfuric acid (20 mL) at 0°C. The resulting red/brown mixture was stirred at reflux for 2 hours and then poured into ~200g of ice to give a yellow slurry. Slowly add 10NNaOH to the mixture until pH~12, then extract the mixture with CH₂Cl₂ (3×50mL) and dry (Na₂ sub>SO₄), filtered and concentrated in vacuum to obtain the product 2-amino-4-methyl-3 bromopyridine dihydrochloride, 5-dibromopyridine, as a light orange solid, yield 5.35 g, 54%. ¹HNMR (CDCl₃) δ2.51 (s, 3H), 4.94 (brs, 2H), 8.05 (s, 1H).

Methylpyridine

Preparation method and application of 2-amino-4-methyl-3,5-dibromopyridine

PCT Int. Appl., 2000021963 reported that 2-amino-4-methyl-3,5-dibromopyridine can be used to prepare intermediate 6, which can be further processed using palladium-catalyzed arylation, Heck reaction or carbonylation. The bromine substituent on intermediate 6 can be modified, or alternatively, IL-8 receptor antagonists can be prepared using nucleophilic conditions such as sodium alkoxide, azide, thiol, or cyanide to replace bromide. PCT Int. Appl., 2000021963 provides a method of treating a chemokine-mediated disease, wherein the chemokine is a chemokine that binds to an IL-8a or b receptor, and the method includes administering an effective amount IL-8 receptor antagonists or pharmaceutically acceptable salts thereof, chemokines, especially IL-8.