6-BROMOIMIDAZO[1,2-A]PYRIDINE-3-CARBALDEHYDE

Step 1: 6-bromoimidazo [1, 2-a] pyridine-3-carbaldehydeBromomalonaldehyde (5230 mg, 34.68 mmol) was added to a solution of 5-bromopyridin-2- amine in acetonitrile (5000 mg, 28.90 mmol). The reaction mixture was refluxed for 2 hours. After completion of the reaction, the reaction mixture was quenched with sodium bicarbonate solution and extracted with EtOAc. The organic layer was washed with brine and dried over sodium sulfate. The organic layer was concentrated in vacuo and the product was purified by column chromatography using EtOAc -petroleumether gradient to obtain the title compound. Yield: 53 percent; H NMR (DMSO-dGeneral procedure: 6-bromo-2-aminopyridine (0.208 g, 1.2 mmol, 1 eq.) and 2-bromomalonaldehyde (0.272 g, 1.8 mmol, 1.5 eq.) were dissolved in the mixture of ethanol and water (v/v 1:1, total 2 ml) and placed in the pressure vial, equipped with a magnetic bar. The mixture was stirred for 1 min and purge with argon via syringe. Then microwave (MW) irradiation (with initial 150 W power) was applied. Depending on the substituents present in 2-aminopyridine 1, the following conditions were applied: a) for 2-aminopyridines substituted with halogen, or nitro or cyano groups: 10 min, 110 C; or b) for 2-aminopyridines substituted with methyl or phenyl groups: 20 min, 100 C. Afterwards, the reaction mixture was evaporated. Next the reaction mixture was neutralized with TEA, diluted with DCM (10 mL), and adsorbed on silica gel (~3 g).* The solvent was evaporated, and the residue was subjected to column chromatography using gradient DCM/acetone (100:0 => 75:25) as eluent to give product as yellow powder.

Molecular Weight:225.04
XLogP3:2.2
Hydrogen Bond Acceptor Count:2
Rotatable Bond Count:1
Exact Mass:223.95853
Monoisotopic Mass:223.95853
Topological Polar Surface Area:34.4
Heavy Atom Count:12
Complexity:188
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes