Hoshino & Shimodaira (1936): First Synthesis of 5-MeO-DMT and Bufotenin
One-line verdict: The 1936 paper that proved the structure of bufotenin and 5-MeO-DMT by total synthesis, establishing the synthetic chemistry foundation for an entire class of psychoactive tryptamines.
Source confidence: High. Peer-reviewed synthetic chemistry with full experimental characterization, melting point comparisons against authenticated natural products, and elemental analysis. The gold standard of structural proof for its era.
Why This Matters
This is the origin point for synthetic access to 5-MeO-DMT and bufotenin. Every subsequent pharmacological, phenomenological, and therapeutic study of these compounds (including the intranasal 5-MeO-DMT clinical trial in NOTES_5-MeO-DMT_intranasal_phase1) depends on the structural certainty this paper established. For the Web of Psychedelics, this fills a gap: the project documents the pharmacology and phenomenology of tryptamines, but not their synthetic history. This paper is the earliest synthetic landmark for the 5-MeO-DMT/bufotenin pair.
Key Ideas
1. First total synthesis of 5-MeO-DMT via an indole alkylation route
Hoshino built the molecule from 5-methoxyindole-3-acetic acid through a four-step sequence: hydrolysis, esterification, Bouveault-Blanc reduction to tryptophol, bromination, then nucleophilic displacement with dimethylamine. This “bromide + amine” strategy became the template for tryptamine synthesis for decades.
Connects to: Tryptamines (Web of Psychedelics substance class). This paper is the first synthetic entry for the tryptamine class, predating Shulgin’s systematic exploration by 60 years. The Tryptamines page currently lacks historical synthesis context. Connects to: Glossary (entry on 5-MeO-DMT). The glossary describes 5-MeO-DMT as “naturally occurring” from toad secretions and plants. This paper adds the synthetic dimension: it was made in a lab in 1936, before its role as a psychoactive compound was even recognized.
2. Structural proof of bufotenin by synthesis
By converting synthetic 5-MeO-DMT to bufotenin via AlCl3 O-demethylation and confirming identity with Wieland’s natural isolate (matching pikrate melting points), Hoshino proved bufotenin’s structure unambiguously. Before this, the structure was only inferred from degradation studies.
Connects to: Glossary (entry on Anadenanthera, which mentions bufotenine from plant seeds). Hoshino’s synthesis closed the loop: degradation told you what pieces the molecule contained; synthesis proved how they were assembled.
3. The quaternary ammonium salt route as an alternative pathway
Exhaustive methylation of 5-methoxy-tryptamine with methyl iodide gave the trimethylammonium salt in >90% yield. Hofmann elimination by vacuum pyrolysis then gave 5-MeO-DMT. This is notable because it showed two independent routes to the same product, strengthening the structural proof.
Connects to: HamiltonMorris133 (discussion of INMT enzyme converting tryptamine to DMT). The biological N-methylation of tryptamine mirrors what Hoshino did chemically with methyl iodide. Manske’s observation that chemical methylation gives a hard-to-separate mixture of mono-, di-, and trimethyl products is the synthetic chemist’s version of the selectivity problem that INMT solves enzymatically.
4. Manske’s concurrent work revealed the difficulty of selective tryptamine methylation
R.H. Manske (Canada) showed that reacting tryptamine with methyl iodide gives an inseparable mixture: monomethyl, dimethyl, trimethyl, and recovered starting material. Selective N-methylation of tryptamine is hard because each successive methyl group barely changes nucleophilicity.
Connects to: Glossary (entries on 4-AcO-DMT, 4-HO-MET, 5-MeO-MiPT and other N-substituted tryptamines). Shulgin’s later solutions to the selectivity problem (using different amines rather than sequential methylation) are downstream of the challenge Manske documented here.
5. Connection to the physostigmine (eserine) synthesis program
Hoshino’s tryptamine work was not aimed at psychoactive compounds at all. It was a stepping stone toward synthesizing physostigmine, the cholinesterase inhibitor from Calabar beans. The psychoactive properties of bufotenin and 5-MeO-DMT were incidental to the original research goal.
New territory: No existing vault note covers the physostigmine connection or the broader history of indole alkaloid synthesis programs in the 1930s. Consider a note in _CREATIVE/Web_Of_Psychedelics/02_HISTORY/ on the accidental origins of tryptamine synthesis.
6. Tryptophol as a key synthetic intermediate
The route goes through 5-methoxy-tryptophol, the alcohol analog of tryptamine. This intermediate is biologically relevant: tryptophol is a natural product found in fungi and fermented foods, produced by yeast from tryptophan via the Ehrlich pathway.
Connects to: Paper-Strategy (BiocatMiner). The Paper Strategy discusses RgTDC tryptophan decarboxylase as making biogenic amines (tryptamine, tyramine). Hoshino’s chemical route to tryptamine derivatives parallels the enzymatic route: both start from an indole building block and functionalize the sidechain. The enzymatic path (decarboxylation) is more direct than Hoshino’s (acid to ester to alcohol to bromide to amine).
7. Identity confirmation by “mixed melting point”
The structural proof depended on a now-obsolete technique: mixing synthetic and natural samples and checking that the melting point did not depress. This was the 1930s equivalent of spectroscopic comparison, predating NMR by two decades.
New territory: No vault note covers pre-spectroscopic structural elucidation methods. For a history-of-chemistry note, this is a good example of how structural certainty was achieved before modern instrumentation.
Connection Map
| This source says… | …which links to | Because |
|---|---|---|
| 5-MeO-DMT first synthesized 1936 | Tryptamines | Establishes the synthetic origin date for this entire substance class in the vault |
| Bufotenin structure proved by synthesis | Glossary | Glossary lists bufotenine under Anadenanthera seeds; this is the paper that confirmed the structure |
| INMT-like methylation done chemically | HamiltonMorris133 | Gallimore/Morris discuss enzymatic DMT biosynthesis; Hoshino’s chemical version shows why selective methylation is hard |
| Tryptophan decarboxylase makes tryptamine | Paper-Strategy | BiocatMiner features RgTDC (tryptophan decarboxylase); Hoshino needed 4 chemical steps to reach what the enzyme does in one |
| 5-MeO-DMT pharmacology unknown in 1936 | 04_Psychedelics | The phenomenology EM explores was invisible to the chemists who first made the molecule |
| Intranasal 5-MeO-DMT clinical use | NOTES_5-MeO-DMT_intranasal_phase1 | 90 years from first synthesis to Phase 1 clinical trial of the same compound |
Cross-Domain Bridges
Chemistry (research) to phenomenology (EM/creative): Hoshino synthesized 5-MeO-DMT as a structural proof exercise with zero awareness of its psychoactive properties. The compound that 04_Psychedelics describes as producing “dramatically reduced internal constraint” and that NOTES_5-MeO-DMT_intranasal_phase1 maps phenomenologically was, at birth, just an intermediate on the road to physostigmine. This is a striking example of how the chemical and experiential descriptions of the same molecule can be completely disconnected for decades.
Synthetic chemistry to biocatalysis (research): Hoshino’s 4-step route from indole acetic acid to tryptamine derivative is exactly the kind of transformation that enzymatic approaches now accomplish in a single step. The tryptophan decarboxylases in Glenn’s Chlamydomonas biocatalysis project are the biological solution to the problem Hoshino solved the hard way.
Open Questions
- When was 5-MeO-DMT first recognized as psychoactive? Hoshino clearly did not know. Somewhere between 1936 and the first pharmacological reports, someone made the connection.
- Did Hoshino’s group ever complete the physostigmine synthesis that motivated this entire indole series? The paper is Part XV; the target may have been reached in a later installment.
- The Tryptamines page in Web of Psychedelics is empty. Should this paper anchor a historical synthesis timeline for the tryptamine class?