SYNTHESIS: (from indole): To a well-stirred solution of 1.6 g indole in 30 mL anhydrous Et2O there was added, dropwise over the course of 30 min, a solution of 3.8 g (2.6 mL) oxalyl chloride in 30 mL anhydrous Et2O. Stirring was continued for an additional 15 min during which time there was the separation of indol-3-ylglyoxyl chloride as a crystalline solid. This intermediate was removed by filtration and washed with Et2O. It was used directly in the following step. This solid acid chloride was added to 3.6 g anhydrous ethylisopropylamine in Et2O, followed by the addition of an excess of 2 N HCl. The mixture was cooled, and the resulting product N-ethyl-N-isopropylindol-3-ylglyoxylamide was removed by filtration. The air-dried product weighed 2.2 g (62% yield) and had a melting point of 149–151 °C.

A solution of 2.0 g N-ethyl-N-isopropylindol-3-ylglyoxylamide in 50 mL anhydrous THF was added, dropwise, to 1.5 g LAH in 50 mL anhydrous THF which was well-stirred under an inert atmosphere. This was brought to reflux and held there for 3 h. The reaction mixture was cooled, and the excess hydride destroyed by the cautious addition of wet THF. A 15% NaOH solution was then added until the solids had a loose white cottage cheese character to them, and the mobile phase tested basic by external damp pH paper. These formed solids were removed by filtration, washed first with THF and then MeOH. The filtrate and washings were combined, dried over anhydrous MgSO4, and the solvent removed under vacuum. The residue set up to a crystalline mass weighing 1.6 g (90%). This was recrystallized from pentane to provide N-ethyl-N-isopropyltryptamine (EIPT) as a free base with a mp of 71–73°C. Indole can also serve as a precursor to NET which is easily transformed into EIPT.

(from N-ethyltryptamine, NET): To a solution of 0.33 g N-ethyltryptamine base (see NET recipe) in 4 mL isopropanol there was added 1.5 g isopropyl iodide and 1.2 g diisopropylethylamine, and this was held at reflux for 36 h. The volatiles were removed under vacuum, and to the residual black oil there was added 100 mL 15% aqueous NaOH. This was extracted with 3×50 mL CH2Cl2, the extracts pooled, the solvent removed, and the residue distilled at the KugelRohr to give 0.24 g (59%) of N-ethyl-N-isopropyltryptamine as a pale amber oil, bp 150–160 °C at 0.11 mm/Hg that did not crystallize. MS (in m/z): C6H14N+ 100 (100%); C3H8N+ 58 (58%); indolemethylene+ 130 (11%); parent ion 230 (1%). This base was converted to the hydrochloride salt, as described above.

DOSAGE: 24–40 mg, orally

DURATION: 4–6 hrs h

QUALITATIVE COMMENTS: (with 24 mgs, orally) “There is something strange going on, and I am feeling quite urpy, but I feel quite horny at the same time. What would it be like to be making love and vomiting at the same time? Something is not at peace with itself. No way. And then suddenly I am baseline, and there is nothing left.”

(with 40 mg, orally) “I see some similarities with DET and MIPT orally, not too pleasant with somewhat dysphoric components and visual effects more in the background. Michael Valentine Smith described a ‘little elephant’ as a thing to be found in 5-MeO-DMT. And a little of this is to be found in this drug.”

(with 40 mg, orally) “Within a half hour, I have sparkling and a very unsure tummy. This is on one hand strangely not erotic, and yet I am completely functional, sexually. Remarkable orgasm. But still not erotic. No visuals, no sound enhancement, no fantasy, so why is it up there at a plus 2? I don’t know, and I am pretty much baseline by the fifth hour.”

(with 40 mg, orally) “Within the hour, a very mild pre-nausea, which passed off in about 45 minutes. No visual effects at all. The dreams that night weren’t quite as satisfying as the excellent, nice, clear, pretty dreams with an earlier 30 mg trial. The night was full of chopped-up sleep, since I was up about once an hour to pee. Observation: there is some diuretic component to this material. Barely plus 1. Would not bother taking it again.”

EXTENSIONS AND COMMENTARY: Clearly this is not an exciting compound. So why go to the extensive bother to make it and test it? For the single reason that the diisopropyl analogue is totally weird, one of the two weird tryptamines that need to be explored. If everything went as predicted, then nothing would ever be discovered. One must look always for the aberration that will demand that you change your working hypotheses and become responsive to unexpected and unexplainable things. 5-MeO-DET has an unexpected property, a lightheadedness and vertigo at a very small dosage. This may prove to be its value in research, and this is discussed in its own entry. Here is a response to another unexpected observation. N,N-diisopropyltryptamine causes extraordinary auditory distortions. What about this molecule does this thing? Are both isopropyl groups needed? Is only one needed? Might neither be needed, but simply to have something equally massive stuck to that nitrogen atom? This compound, EIPT, is an essential brick in this wall that will contain, define, and describe the fine details of this remarkable CNS property.

This is why EIPT is interesting. Let me itemize these close relatives of the diisopropylamine analogue, maintaining one isopropyl group but letting the other be something different. What can be seen from all of this exploration?

If it turns out that the diisopropyl substitution is an absolutely essential structural component of this sensory phenomenon, then it has become one of the most remarkable tools known for the study of the human auditory association area in the brain.

This is why all of this research is important. You can never tell what a new compound will do. So you must continue to make new compounds and you must continue to be the observer. It is truly an exciting world.

About TiHKAL • info

This version of Book II of TiHKAL is based on the Erowid online version created by Bo Lawler with the help of Erowid, from content generously provided in electronic format by the Authors.

The Erowid online version does not always match the printed version—I’ve found over 300 inconsistencies. Text has been inserted, deleted, or changed at various points. Perhaps the Erowid version was created from an earlier (or later) draft? In several places the Erowid version is plainly wrong; elsewhere it’s a tougher call. I don’t claim to have found every discrepancy; in those cases I have found, both the Erowid and print versions are given and marked as such. I would be grateful if any sharp-eyed readers would report any I have missed.

As with PiHKAL • info, I’ve again attempted to reproduce the typographic style of the printed edition. And again, I’ve also made minor changes to some chemical names in line with current nomenclature practice, and in the hope of aligning with more readers’ searches. Typically the change is little more than expanding a prefix and setting it in italics. The errata and changes page has further details.

Cautionary Note

“I would like to take a moment to reiterate that at the present time restrictive laws are in force in the United States and it is very difficult for researchers to abide by the regulations which govern efforts to obtain legal approval to do work with these compounds in human beings.

“No one who is lacking legal authorization should attempt the synthesis of any of the compounds described in these files, with the intent to give them to man. To do so is to risk legal action which might lead to the tragic ruination of a life. It should also be noted that any person anywhere who experiments on himself, or on another human being, with any of the drugs described herein, without being familiar with that drug’s action and aware of the physical and/or mental disturbance or harm it might cause, is acting irresponsibly and immorally, whether or not he is doing so within the bounds of the law.”

Alexander T. Shulgin

Copyright Notice

The Copyright for Part 1 of TiHKAL has been reserved in all forms and it may not be distributed. Part 2 of TiHKAL may be distributed for non-commerical reproduction provided that the introductory material, copyright notice, cautionary notice and ordering information remain attached.

Ordering Information

TiHKAL is the extraordinary record of the authors’ years exploring the chemistry and transformational power of tryptamines. This book belongs in the library of anyone seeking a rational, enlightened and candid perspective on psychedelic drugs.

Although Sasha and Ann have put Book II of TiHKAL in the public domain, available to anyone, I strongly encourage you to buy a copy. We owe them—and there’s still nothing quite like holding a real book in your hands.

TiHKAL (ISBN 0-9630096-9-9) is available for US$24.50 (plus $10 domestic first-class shipping) from Transform Press.