Synthesis and Characterization of N-( 3-( 8-Bromoimidazo [ 1 , 2-a ] pyridin-2-yl )-4-Fluorophenyl ) Benzamide Derivatives

We report here the synthesis and characterization of new N-(3-(8-bromoimidazo[1, 2a]pyridin-2-yl)-4-fluorophenyl)benzamide derivatives. This collection was obtained from 3-(8bromoimidazo [1,2-a]pyridin-2-yl)-4-fluoroaniline(5). The family of new compounds was characterized by 1H-NMR, 13C-NMR, FT-IR and LC-MS analysis.


General
All reagents were purchased from Merck and Aldrich and used without further purification.
The NMR spectra were recorded on a Bruker Avance DPX 400 MHz instrument.The spectra were measured in DMSO-d6 relative to TMS (0.00 ppm).Elemental analysis was performed on a Heraeus CHN-O-Rapid analyzer.TLC was performed on silica gel Polygram SIL G/UV 254 plates.

Synthesis of 1-(2-fluoro-5-nitrophenyl)ethanone (2):
A stirred solution of (2-fluorophenyl)ethanone (10 g, 0.0723 mol) in Con sulfuric acid (40 mL, 4V) was cooled to -5°C to -10°C.To this yellow stirred suspension was added drop wise a mixture of Con sulfuric acid : Con nitric acid (14 mL: 8 mL) at same temperature in the period of 30 min.A yellow color thick suspension was stirred for 10 min at same temperature and monitored by TLC /LCMS.After 10 min TLC shows complete consumption of starting material, the reaction mixture was drop wise poured in ice cold water (500 mL, 50 V).The yellow precipitated solid was filtered and washed with water (50 mL, 5V).The yellow solid was taken in dichloromethane (100 mL, 10V) and washed with brine solution (50 mL, 5V).Organic layer was concentrated at -30°C to -35°C and co-evaporated with hexane (50 mL, 5V).The yellow crude solid was suspended in hexane (50 mL, 5V) and cooled to 0°C to 5°C then stirred for 1h at same temperature.The yellow solid was filtered and washed with hexane (20 mL, 2V) then dried under vacuum to afford the pale yellow solid (11 g, 83%).The reaction mixture was monitored by TLC/LCMS.After completion of starting material the reaction mixture was quenched with ice cold water (250 mL, 25 V).Two layers were separated and organic layer was washed with 10% sodium bicarbonate (100 mL, 10V) and brine solution (100 mL, 10 V).Organic layer was concentrated concentrated at -30°C to -35°C.The yellow gammy solid was taken in methanol (2 mL, 2 V) and cooled to -15°C to -20 °C then stirred for 1h.The precipitated solid was filtered and dried under vacuum to afford the off white solid (7.General procedure for the synthesis final coupling 5a-5e :

Results and discussion:
The synthesis of imidazo

Conclusion:
In conclusion, we have designed and synthesized new substituted imidazo[1,2-a] pyridazine derivatives with different substituted benzoic acid couplings with amino compound-5 and characterized through spectral analysis.