tert-Butyl 2,6-Diazaspiro[3.4]octane-6-carboxylate is used as a reagent in the synthesis of spirodiamine-diarylketoxime derivatives as melanin concentrating hormone (MCH-1R) antagonists. Also used as a reagent in the synthesis of dihydroisoindolecarboxamide derivatives as NAMPT and ROCK inhibitors.