* All experimental methods are cited from the reference, please refer to the original source for details. We do not guarantee the accuracy of the content in the reference.
With pyridine In dichloromethane for 14h; Heating / reflux;
17 Preparation 17; Preparation of N-Acetyl-N-(6-bromo-imidazo[1,2-a]pyridin-3-yl)-acetamide
Add trifluoroacetic acid (10 ml) to a solution of (6-bromo-imidazo [1, 2-a] pyridin- 3-YL)- (1, 1, 3, 3-TETRAMETHYL-BUTYL)-AMINE (prepared in a manner similar to Preparation 12; 0.5 g, 1.54 mmol). Reflux for 1 h and concentrate to dryness. Flash chromatography using ethyl ACETATE/METHANOL mixtures gives the off-white solid intermediate 6-bromo- imidazo [1, 2-a] pyridin-3-ylamine ES+m/e 213.6 (bromine isotopes) (M+1). Immediately dissolve intermediate in dichloromethane and add pyridine (1 g, 12.64 mmol) followed by acetic anyhydride (1.5 g, 14.69 mmol) and reflux for 14 h. Concentration followed by purification by flash chromatography gives 0.38 g (83%) of the title compound. ES+ M/E 297.7 (bromine isotopes) (M+1).
With hydrogenchloride In isopropyl alcohol at 20℃; for 24h; Inert atmosphere;
With trifluoroacetic acid for 1h; Heating / reflux;
17 Preparation 17; Preparation of N-Acetyl-N-(6-bromo-imidazo[1,2-a]pyridin-3-yl)-acetamide
Add trifluoroacetic acid (10 ml) to a solution of (6-bromo-imidazo [1, 2-a] pyridin- 3-YL)- (1, 1, 3, 3-TETRAMETHYL-BUTYL)-AMINE (prepared in a manner similar to Preparation 12; 0.5 g, 1.54 mmol). Reflux for 1 h and concentrate to dryness. Flash chromatography using ethyl ACETATE/METHANOL mixtures gives the off-white solid intermediate 6-bromo- imidazo [1, 2-a] pyridin-3-ylamine ES+m/e 213.6 (bromine isotopes) (M+1). Immediately dissolve intermediate in dichloromethane and add pyridine (1 g, 12.64 mmol) followed by acetic anyhydride (1.5 g, 14.69 mmol) and reflux for 14 h. Concentration followed by purification by flash chromatography gives 0.38 g (83%) of the title compound. ES+ M/E 297.7 (bromine isotopes) (M+1).