Pyridine → HCID 69603267, compound

The 2-[2-(4-methoxybenzyl)-2H-1,2,3,4-tetrazol-5-yl]ethanoyl chloride (0.27 g, 1.05 mmol) obtained in (C) was dissolved in methylene chloride (3 ml), added dropwise with pyridine (170.2 μl, 2.10 mmol) under ice cooling, and added dropwise with a solution of 8-[2-(4-isopropyl-1,3-thiazol-2-yl)ethyl]-2-morpholino-4 H-pyrido-[1,2-a]pyrimidin-4-one (80.9 mg, 0.21 mmol) in methylene chloride (3 ml). The reaction solution was stirred at room temperature for 23 hours, then further added with a solution of 2-[2-(4-methoxybenzyl)-2H-1,2,3,4-tetrazol-5-yl]ethanoyl chloride (0.27 g, 1.05 mmol) in methylene chloride (2 ml) and pyridine (170.2 μl, 2.10 mmol) under ice cooling. Further, the reaction solution was added with the same amounts of the acid chloride and pyridine twice every 24 hours, and stirred at room temperature. The solvent was evaporated, and the residue was added with saturated aqueous sodium hydrogencarbonate and extracted with ethyl acetate. The organic layer was washed with saturated brine and dried over anhydrous sodium sulfate. The solvent was evaporated and the residue was purified by preparative TLC (hexane:ethyl acetate=1:1, v/v and chloroform:methanol=30:1, v/v) to obtain the title compound (10.1 mg, 7.8%) as yellow oil.