AH-7921 is a relatively new research chemical and one of thew few opioid analgesics available on the research chemical market. AH-7921 is selective for the mu opioid receptor and thought to have roughly the same potency as morphine.
Very little information about this drug exists on the web. It is rumored that some offshore laboratories are trying to synthesize AH-7921. It is expected to be available for purchase within the next few months.
This post from Opiophile suggests that it is easy to prepare at home. The only information on LHG regarding this substance can be found in this thread. The user appears to be trying to organize multiple buyers to secure 10 purchases for the substance.