chemistry

NDTDI

NDTDI is a chemistry topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand NDTDI rather than just read about it. In short: NDTDI, also known as 9-desmethine-LSD, 9-nor-LSD, or 8,10-seco-LSD, is a psychedelic drug related to lysergic acid diethylamide (LSD). It is a tricyclic cyclized tryptamine and partial lysergamide and is a structurally simplified analogue of LSD.

Key takeaways

NDTDI belongs to chemistry; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect NDTDI to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of NDTDI from memory before moving on to harder problems.

Reference excerpt

NDTDI, also known as 9-desmethine-LSD, 9-nor-LSD, or 8,10-seco-LSD, is a psychedelic drug related to lysergic acid diethylamide (LSD). It is a tricyclic cyclized tryptamine and partial lysergamide and is a structurally simplified analogue of LSD. The drug is specifically the analogue of LSD in which the carbon atom at position 9 of the ergoline ring system has been removed. It has been reported to produce psychedelic effects similarly to LSD, but with much lower potency. The pharmacology of NDTDI has not been studied. NDTDI was encountered as a novel designer drug by 2016.

Interactions

Chemistry

Analogues Analogues of NDTDI include RU-27849, RU-28306, RU-28251, Bay R 1531 (LY-197206), LY-293284, and LY-178210. Other partial/simplified lysergamides include DEIMDHPCA (4-nor-LSD), DEMPDHPCA (dides-B,C-LSD), and 10,11-seco-LSD, among others. Deletion of the carbon at positions 9 and 10 of the ergoline ring system result in a fully non-rigid tryptamine derivative, N-DEAOP-NMT (9,10-dinor-LSD).

History NDTDI has been sold as a designer drug since 2016 and was first identified by a forensic laboratory in Slovenia in 2017. NDTDI was made illegal in Latvia in March 2017.

Society and culture

Legal status

Canada NDTDI is not an explicitly nor implicitly controlled substance in Canada as of 2025.

United States NDTDI is not an explicitly controlled substance in the United States. However, it could be considered a controlled substance under the Federal Analogue Act if intended for human consumption.

See also Partial lysergamide List of miscellaneous 5-HT2A receptor agonists Seco-LSD

References

External links NDTDI - Isomer Design Hallucinogens You Probably Haven't Heard of: Tricyclic Tryptamines - Nervewing - Blogger The Small & Handy NDTDI Thread - Bluelight

Illustrations

Worked examples

Example 1 — a first encounter with NDTDI

Start with the simplest possible case. Write down what NDTDI claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In chemistry, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to NDTDI before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about NDTDI ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of NDTDI

In research: NDTDI appears in chemistry research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses NDTDI in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: NDTDI is common in secondary-school and first-year university syllabi. It links to neighbouring topics Alpha-Alkyltryptamines, Carboxamides, Diethylamides, so understanding it makes those chapters shorter.
In everyday life: Look for NDTDI outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study NDTDI in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what NDTDI means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain NDTDI out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is NDTDI in simple terms?

Why does NDTDI matter?

Because it connects several chemistry ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study NDTDI?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on NDTDI.