The legal distinctions you draw are over the head of the drug interdiction officers who do the actual searches, seizures, and busts. They fill out their paperwork and turn it in to the DA who decides whether there is enough admissible evidence to make the case, and if it does, charges are filed. Trying to persuade a guy with a badge on his shirt and a gun on his hip that your home chemistry is not drug related is a waste of your breath, and his time. His presence derives from his suspicion that you are involved in making illegal drugs, and he expects you to claim you are making something else. If he finds a lab in your garage, or secreted away where it should not be noticed, he will consider that evidence of your knowledge that what you are doing is in violation of the law.
The definition of analogue is not as tight a definition as you think it is.
In order for you to violate the analogue substance law the chemical structure must be substantially similar to the chemical structure of a controlled substance in schedule I or II; in addition to this requirement, the substance must have a stimulant, depressive or hallucinogenic effect on the central nervous system that is similar substantially similar to or greater than the stimulant, depressant, or hallucinogenic effect on the central nervous system of a controlled substance in schedule I or II; OR the defendant
intended the substance to have, or
represented that the substance in fact had, the stimulant, depressant or hallucinogenic effect on the CNS system of a controlled substance in schedule I or II.
In
U.S. v Forbes, 806 F.Supp. 232 (D. Colo., 1992) to US District Court in Colorado analyzed the statute and commented
"The term "controlled substance analogue" is defined to conform as closely as possible to the policy of the Controlled Substances Act by requiring a chemical relationship to a substance which is controlled ... and either the existence of some stimulant, depressant, or hallucinogenic effect on the central nervous system, or a representation or intent that the substance have a stimulant, depressant, or hallucinogenic effect substantially similar to, or greater than, such effect of any controlled substance....
The analogue statute is directed at underground chemists who tinker with the molecular structure of controlled substances to create new drugs that are not scheduled. If a substance could be an analogue without a substantially similar chemical structure, Congress' stated purpose would be significantly expanded. Moreover, by essentially adopting the House definition, Congress evidenced its intent to require a two-pronged definition.
Additionally, the government and defense experts who testified agree that the question of structural similarity must, in part, be evaluated in conjunction with the molecule's hallucinogenic and stimulant activity. Because structurally similar substances have similar pharmacological effects on the central nervous system, a finding of such similar effects is some indication that the molecular structures should be classified as substantially similar. The scientific interdependence of molecular structure and effect on the central nervous system is consonant with the legislative history evidencing congressional intent to establish a dependent, two-prong test...
Therefore, I hold that a substance may be a controlled substance analogue only if it satisfies clause (i) and clauses (ii) or (iii)."
Most federal circuits follow a similar analysis of the statute, although they are not in complete agreement on its meaning. The common thread in the federal appellate decisions is that the analogue act applies to substance which either are substantially similar either in chemical structure or net effect to any schedule I or II controlled substance. The issue of how substantial the similarity is is for the trier of fact, usually a jury. The cases involving the analogue act include cases where both the government and the defense called chemistry experts as witnesses and those witnesses could not agree on the question of whether two chemicals were "substantially similar" for purposes of the act. The cases indicate that the question of whether the substantial similarity test has been met is a question for the jury, and the jury is not bound by the opinion of any particular witness.
Your question was whether a person who ordered a precursor to a schedule IV drug which has no stimulant, depressant, or hallucinogenic effects, and the person could show to the satisfaction of the trier of facts the precursor was being used for structural identification and research was subject to being charged for manufacturing an analogue. The answer to the question is that he may in fact be charged with an offense, and he may be found guilty of violating the analogue substances act. Note that one can be charged with an offense even if he is not guilty. Charging an offense is supported by the probable cause standard, whereas conviction requires proof beyond a reasonable doubt. A cop looking at a condenser and flask on a hotplate could easily be said to have probable cause that a controlled substance or analogue was being manufactured. The test is not whether he has evidence that you are in fact guilty. The test is whether he has a reasonable factual basis for concluding that criminal activity may be occurring. That is a far simpler test than guilt. The people who decide guilt are normally juries, although often juries are waived and the guilt issue is tried to a judge alone. You can be innocent and be charged with a crime. You can be innocent and be convicted, as the numerous post conviction reviews based on dna evidence have proved beyond doubt. The fact that your esteemed chemist Ph.D. expert witness is prepared to testify that the substances are chemically dissimilar is for the jury to take as they wish. The fact that government witnesses could not agree on whether two compounds were "substantially similar" was found of consequence in the
Forbes opinion to preclude a conviction. Other courts have ruled the issue is one of fact for a jury to decide, and some circuits have held that differences of opinion on whether a drug is substantially similar to another drug does not depend on the nature of the drug, but how it is metabolized in the human body.
As to concerns about being arrested for analogue drugs, the fact that you are working in a home lab and (most likely) under circumstances that tend to conceal or obscure the use put to the premises can be considered as evidence of guilty knowledge. The same conduct, committed in a business in a commercial or industrial district, would not necessarily provide that inference. If you were in fact not making or trying to make something similar to a controlled drug and were conducting your work at a business or industry address, the nature of the work being done might be substantially less suspicious because of the apparent business nature of the operation.
If your question goes to whether you can be convicted, your factual assumptions are favorable for your defense, but understand you still have to persuade the trier of fact that you are sincere when you say you were not trying to create a drug. It remains a defense, and something for a trier of fact to decide. That puts you in jeopardy of doing time if they get it wrong. Yes, there is a risk in what you do. The more you do this in the manner a legit business would do it, the less likely it is that you would be charged.
Understand the schedule of the precursor substance does not control the determination. Pseudo is schedule V in my state, and it is behind pharmacy counters because it can be used as a precursor to a schedule II substance.
I have the feeling you may need to rethink your question a bit more to get the answer you are looking for. I may be close, but I think you are actually more concerned about the appearance of what you are doing than the risk of being arrested for it.
but too fuckin true :'(