Is it a controlled drug (anywhere in the world not just where you are)? If the answer is yes then enquiring on how to access it would be breaking the sourcing rule. Same deal if you were trying to access large amounts of a non controlled precursor with a mind to producing a controlled drug.
Basically if the end result is crime in any capacity it's no Bueno.
If for example you already had say something like say cocodimol (paracetamol and codeine) and wanted to ask how to separate them, cwe for example, then my understanding is that's okay.