[CH3:1][O:2][C:3]1[CH:20]=[CH:19][C:6]([CH2:7][N:8]2[N:12]=[N:11][C:10]([CH2:13][C:14]([O:16]CC)=[O:15])=[N:9]2)=[CH:5][CH:4]=1.[OH-].[Li+]>O1CCCC1.CO.O>[CH3:1][O:2][C:3]1[CH:20]=[CH:19][C:6]([CH2:7][N:8]2[N:12]=[N:11][C:10]([CH2:13][C:14]([OH:16])=[O:15])=[N:9]2)=[CH:5][CH:4]=1The ethyl 2-[2-(4-methoxybenzyl)-2H-1,2,3,4-tetrazol-5-yl]acetate (2.15 g, 7.78 mmol) obtained in (A) was dissolved in tetrahydrofuran/methanol (3:1, v/v, 60 ml), added dropwise with a solution of lithium hydroxide (359.2 mg, 8.56 mmol) in water (15 ml) under ice cooling and then stirred at room temperature for 2 hours. The solvent was evaporated, and the residue was added with 1 N aqueous hydrochloric acid to obtain pH of about 1. The solution was extracted with ethyl acetate, and the organic layer was washed with saturated brine and dried over anhydrous sodium sulfate. Then, the solvent was evaporated to obtain the title compound (1.91 g, 98.8%).
Loading…