A paper says the following,
Dichloroglyoxime was prepared by chlorination of glyoxime in 10 % HCl at 0 deg C and crystallized from toluene.
When they say "crystallized from toluene" do they unambiguously mean recrystallized from boiling toluene at standard pressure? Thermally these compounds are unstable and instead of a white nice product I've ended up with a purple one much to my dismay and I'm not sure what actually causes the purple.
I've had problems with this synthesis because the $^1$H NMR always shows more than one oxime environment.