1: [1,2,4]triazolo[1,5-a]pyridine-6-carboxylic acid ethyl ester With sodium hydroxide; water in tetrahydrofuran 2: With hydrogenchloride; water in tetrahydrofuran 3: O,N-dimethyl-hydroxylamine hydrochloride With pyridine; oxalyl dichloride; N,N-dimethyl-formamide more than 3 stages;