A facile and convenient synthesis of new substituted heteroarylchalcones and flavones by microwave irradiated Suzuki-Miyaura cross coupling reaction in aqueous medium was written by Joshi, Vidya;Hatim, Jaywant Govind. And the article was included in Indian Journal of Heterocyclic Chemistry in 2012.COA of Formula: C4H5BrN2 This article mentions the following:
Chalcones I (R = heteroaryl) and corresponding flavones II (same R) having various heteroaryl substituents have been synthesized. The starting compound 5-formyl-2-methoxyphenylboronic acid (III) was prepared by a series of reactions; bromination of 4-methoxybenzaldehyde with catalyst anhydrous AlCl3 in DCE (1,2-dichloroethane) gave 3-bromo-4-methoxybenzaldehyde. The aldehydic in 3-bromo-4-methoxybenzaldehyde was protected by acetalization with 1,3-propanediol and Et orthoformate with phase transfer catalyst tetrabutylammonium tribromide producing the corresponding 2-(3-bromo-4-methoxyphenyl)-1,3-dioxane, which on treatment with tri-Me borate [(MeO)3B] in presence of n-butyllithium at 70° gave III. Suzuki-Miyaura coupling of III with different heteroaryl bromides in presence of [(C6H5)3P]4Pd(0) catalyst, aqueousNa2CO3 (2N) as base, and aqueous DMF as solvent and microwave irradiation for 1 to 2.5 min. in a Panasonic microwave set at 1000 W and 80% microwave power yielded 3-heteroaryl-4-methoxybenzaldehydes. Claisen-Schmidt condensation of the latter with 2-hydroxyacetophenone in presence of ethanolic KOH produced 3-heteroaryl-2′-hydroxy-4-methoxychalcones (I, R = heteroaryl). Cyclizing I with a mixture of I2 and DMSO gave 3′-heteroaryl-4′-methoxyflavones (II, same R). In the experiment, the researchers used many compounds, for example, 4-Bromo-1-methylimidazole (cas: 25676-75-9COA of Formula: C4H5BrN2).
4-Bromo-1-methylimidazole (cas: 25676-75-9) belongs to imidazole derivatives. Many natural products, especially alkaloids, contain the imidazole ring. These imidazoles share the 1,3-C3N2 ring but feature varied substituents. Many drugs contain an imidazole ring, such as certain antifungal drugs, the nitroimidazole series of antibiotics, and the sedative midazolam.COA of Formula: C4H5BrN2
Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem