Optimization Studies on Synthesis of <scp>TKX</scp>‐50

Abstract

Abstract A systematic study of TKX ‐50 and ABTOX synthesis using both Klapötke and Tselinskii modified procedures is described. The influence of temperature, moisture, acid amount and nature on the most critical synthesis step – diazidoglyoxime cyclization is shown. Experimental results show that presence of moisture in reaction mixture leads to product yield decreasing. The reaction temperature is another key parameter affecting product yield. High reaction temperature shows negative influence on the product yield in Klapötke method. In Tselinskii procedure the yield of product grows with the reaction temperature increasing. For Klapötke one‐pot method, combination of N ‐methyl‐2‐pyrrolidone with 1,4‐dioxane is the best solvent, whereas Tselinskii one‐pot procedure gives high yield of product when combination of toluene with 0.5 equiv. of 1,8‐diazabicyclo[5.4.0]undec‐7‐ene ( DBU ) is used. Using optimized conditions one‐pot five‐step synthesis of TKX ‐50 starting from glyoxime is successfully performed and scaled up to 50 g.