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.