I don't know anything about Fentanyl, but something about this description seems off to me. If it's as easy to make as you describe, why wouldn't people just make it here already? Why are they taking the risk of smuggling it across borders?
Most criminals aren't capable chemists. Given a laboratory and barrels of precursor chemicals, they couldn't make perfectly legal drugs like ibuprofen either. Most capable chemists aren't willing to risk property seizure and incarceration to make drugs for the black market. The few capable criminal chemists and their laboratories are concentrated in places where law enforcement is weak, like gang controlled regions of poorer countries.
