\chemfig{CH_3-[:108,,1]N-[:54](-[:180,0.85,,,draw=none]\mcfcringle{1.03})%
-[:126]N-[:198]-[:270](-[:342]\phantom{N})-[:210](=[:270]O)-[:150]N(%
-[:210,,,2]H_3C)-[:90](=[:150]O)-[:30]N(-[:330])-[:90,,,1]CH_3}