[H-].[Na+].Cl[C:4]1[N:9]2[CH:10]=[CH:11][N:12]=[C:8]2[CH:7]=[CH:6][CH:5]=1.[NH2:13][CH2:14][CH2:15][CH2:16][CH2:17][OH:18].C(OC([O-])=O)(OC(C)(C)C)=O>CN(C=O)C>[NH2:13][CH2:14][CH2:15][CH2:16][CH2:17][O:18][C:4]1[N:9]2[CH:10]=[CH:11][N:12]=[C:8]2[CH:7]=[CH:6][CH:5]=1To a suspension of 60% sodium hydride (oily; 1.32 g, 33 mmloes) in DMF (60 ml) was added a solution of 5-chloroimidazo[1,2-a]pyridine (4.59 g, 30.1 mmoles) and 4-aminobutanol (2.68 g, 30.1 mmoles) in DMF (60 ml) at room temperature with stirring and the mixture was stirred at the same temperature for 5 hours. Tert-butyl dicarbonate (9.83 g, 45 mmoles) was added to the reaction solution, which was stirred at room temperature for 13 hours. After the solvent was distilled off, water was added to the residue, which was extracted with ether twice, washed with water and dried over anhydrous magnesium sulfate, and then the solvent was distilled off. The residue was dissolved in methanol (20 ml), followed by the addition of conc. hydrochloric acid (20 ml) and stirring at room temperature for 1 hour. After the solvent was distilled off, chloroform was added to the residue, which was washed with 3N NaOH. After drying over anhydrous potassium carbonate, the solvent was distilled off. The residue was purified by column chromatography (eluent: methanol/chloroform=1:5) to obtain 2.53 g of the desired product (40.9%, light brown oily product).
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