To a solution of 3-(4-benzyloxyphenyl)propiolic acid (1 g) and 1-hydroxybenzotriazole hydrate (643 mg) in N-methylpyrrolidone (10 ml) was added WSCD-HCl (912 mg) and the mixture was stirred at room temperature for 10 min. In another flask, diisopropylethylamine (2.31 g) was added to a suspension of 5-hydrazino-2-methoxypyridine dihydrochloride (1.26 g) in N-methylpyrrolidone (4 ml) and stirred at room temperature until all 5-hydrazino-2-methoxypyridine dihydrochloride was dissolved. Thus obtained hydrazine solution was added to the reaction flask and the mixture was stirred at room temperature for 1.5 hrs.
