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Book II of PiHKAL: A Chemical Love Story, by Alexander & Ann Shulgin #71: DOPR
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#71 DOPR: 2,5-Dimethoxy-4-n-propylamphetamine

#71 DOPR SYNTHESIS: A suspension of 285 g mossy zinc in 285 mL H2O containing 5.7 g mercuric chloride was treated with 285 mL concentrated HCl and shaken as needed to effect amalgamation. The H2O was then drained off, the zinc washed with fresh water and drained again. There was added a solution of 74 g 2,5-dimethoxypropiophenone (from the reaction of propionic acid and p-dimethoxybenzene in the presence of polyphosphoric acid, see under DOAM for an effective general procedure) in 140 g EtOH. The reaction mixture was held at reflux for 24 h with the periodic addition of concentrated HCl. It was then cooled, diluted with H2O and CH2Cl2, and the organic phase separated. The aqueous phase was extracted with 2×100 mL additional CH2Cl2. The combined organic phases were washed with 5% NaOH until the washes remained basic, once with H2O, and then the solvent was removed under vacuum. The residue was distilled at the water pump, giving an early fraction quite rich in starting p-dimethoxybenzene, and a second fraction (61 g, bp 140–160 °C) which was free of carbonyl group by infra-red, and which was largely 2,5-dimethoxypropylbenzene. It was used without further purification in the following aldehyde synthetic step.

A mixture of 124 g N-methylformanilide and 140 g POCl3 was allowed to stand until there was the development of a strong red color. There was then added 60 g of the above 2,5-dimethoxypropylbenzene and the mixture was held on the steam bath for 2 h. The mixture was added to 2 L H2O and stirred until the excess acid chloride had completely decomposed. The mixture was extracted with 3×100 mL CH2Cl2 and, after the removal of the solvent from the combined extracts, the residue was extracted with 3×100 mL boiling hexane. Removal of the solvent gave the product 2,5-dimethoxy-4-propylbenzaldehyde as an oil, 23 g, which was characterized as its malononitrile derivative. Equal weights of the product and malononitrile in EtOH with a catalytic amount of triethylamine gave yellow crystals which, on recrystallization from toluene, had a mp of 113–114 °C.

A solution of 21.5 g of the above crude 2,5-dimethoxy-4-propylbenzaldehyde in 75 g acetic acid, was treated with 10.4 g nitroethane and 6.6 g anhydrous ammonium acetate. This was heated on the steam bath for 1.75 h, then cooled and diluted with H2O to the point of turbidity. With long standing and scratching, there finally was the deposition of crystals which were removed by filtration and sucked as dry as possible. This 23 g of crude product cake was triturated under MeOH, filtered again, and air dried to give 11 g of dull orange crystals. Recrystallization from boiling MeOH gave 1-(2,5-dimethoxy-4-n-propylphenyl)-2-nitropropene as fine orange crystals which weighed, after filtering, washing, and drying, 7.4 g, and which had a mp of 94–96 °C.

To a suspension of 6.0 g LAH in 500 mL anhydrous Et2O, which was being stirred and also held as a gentle reflux, there was added a saturated solution of (2,5-dimethoxy-4-n-propylphenyl)-2-nitropropene in warm THF. The reaction mixture was held at reflux for 24 h, then cooled to room temperature. The excess hydride was destroyed by the cautious addition of 500 mL dilute H2SO4. The phases were separated, and the aqueous phase washed with additional Et2O. There was then added 150 g potassium sodium tartrate, and the pH was brought to >9 with aqueous NaOH. The product was extracted with Et2O and, after removal of the solvent, the residue was dissolved in 200 mL anhydrous Et2O and saturated with anhydrous HCl gas. The solids that formed were removed by filtration, giving 6.15 g 2,5-dimethoxy-4-n-propylamphetamine hydrochloride (DOPR) as an electrostatic, white crystalline powder, with a mp of 182.5–183 °C. This was not improved by recrystallization from either IPA or CH3CN.

DOSAGE: 2.5–5.0 mg.

DURATION: 20–30 h.

QUALITATIVE COMMENTS: (with 2.0 mg) “The onset is slower than any other thing I can think of. There was nothing at all at the end of an hour, and only a threshold a half hour later. By the middle of the third hour, I was up to 1+, and that seemed to be about as high as it intended to take me. Attempts to sleep at the ninth hour were not successful, as there were strange patterns of not-quite logical thinking going on. Stuff like: ‘The block events (like a baby’s rectangular building blocks) that were gotten, along with other things, from the full octaves of the left hand in Listz’s Hungarian Rhapsody, events that allowed an easy recognition of the odds of achieving successful re-entry from any of several erotic codes.’ Clearly this was not a baseline state. After six hours of successful sleep, I was still off-baseline, and on into the following day. Go on up with curiosity but with caution.”

(with 3.6 mg) “Imagery that was constructed in response to the music turned out to be necessary to organize and contain it. The trio is the nucleus that transforms the written to the heard, but it has created its own bubble without connections to the real world, and must play on and on and on to keep itself afloat and never touching the stage again.”

(with 5.0 mg) “I am now at midnight, and still strongly +++. This is certainly maximum dosage, at least for a long time. There are faint intimations of nervous system scrungies. You know, the kind of thing that makes you figure it’s going to be a while before you’ll try to relax into sleep. This material, like all the other DO’s, is a heavy duty psychedelic, the kind that says to you, ‘Forget all that stuff about screening out visuals,’ and then proceeds to prove it. Sort of indole-like in that way. Your body as well as your mind tells you you’re into it, baby, and better relax and enjoy the trip, because you’ve left the shore way behind. When it was time for bed, I got to sleep with surprising ease, and slept for only about six hours. My dreams were excellent, balancing, and good humored. But the next day I realized I was still carrying the DOPR in me, and that baseline was definitely not there. But it was OK. No problems except for sleepiness. The next evening I went to bed at unheard-of hour of 9 p.m. and slept for 13 hours, give or take. Fascinating compound, but I won’t go out of my way to take it again soon.”

EXTENSIONS AND COMMENTARY: There is a thread of disconnection and of inconsistent reference that pervades most of the reports that I have received concerning the use of DOPR. The word that comes to mind is hypnogogic. There is a drifting into that place that lies between a not-quite-awake and a not-quite-asleep state seems to characterize this compound. There is no question but that it is very potent, and that it is very long-lived. But there is a nagging suggestion of the out-of-body, out-of-center character that is the hallmark of the anesthetic and delusional drugs such as scopolamine or ketamine. With them, the psychedelic effects become clouded with touches of amnesia. If DOPR shows this with it’s three carbon alkyl group, thereis every reason to pay close attention as the chain becomes longer.

There had been quite a bit of speculation in the literature that the metabolic attack on DOM was at the 4-position, and this was an oxidation process. In a moment of inspiration, I decided to explore a similar oxidation step in DOPR, since it is probably the most potent of the DO-series. Why not make the compound which would be the first step in this oxidation, the 1-hydroxypropyl analogue? This I did, by using the phthalimide derivative of 2,5-dimethoxyamphetamine (described in the synthesis of DOI) and making the propiophenone using propionic acid as both reagent and solvent, and polyphosphoric acid as the condensing agent. The ketone product (a white crystalline solid from methanol) was dissolved in warm methanol and reduced to the alcohol with sodium borohydride. This product, also a white crystalline solid, was stripped of the phthalimide blocking group with overnight refluxing with hydrazine in ethanol. The product, 2,5-dimethoxy-4-(1-hydroxypropyl)amphetamine (hydroxy-DOPR) had a mp of 148–150 °C from IPA. Its activity is not yet known, but there were no effects at all at trials, orally, of up to 200 micrograms.

But this is all with the n-propyl compound. There is a rich collection of misinformation and potential discovery that is associated with the isopropyl isomer. This structural isomer, 2,5-dimethoxyl-4-isopropylamphetamine is properly called DOIP for des-oxy-isopropyl. It has been synthesized and explored in animals and, to a modest extent, in man. The synthesis has proceeded from 2,5-dimethoxyacetophenone by the addition of a methyl group to the carbonyl followed by reduction to the hydrocarbon. Aldehyde formation, nitropropene synthesis with nitroethane, and lithium aluminum hydride reduction are uneventful, providing the hydrochloride salt DOIP, which has a mp of 183–184 °C as an analytical sample. Animal tests (such as rabbit hyperthermia assays), have indicated that the isopropyl compound DOIP is less potent than the propyl prototype, DOPR, by between one and two orders of magnitude. In man, a dose of four milligrams, a rousing dose of DOPR, is without any effects. At 10 milligrams, there is some disturbance but substantially no effects. I have been told that with doses in the 20 to 30 milligram range there are valid changes in mental state, but I have not been told the nature of these changes.

A fascinating red herring had been drawn across all of these exacting lines by a strange visitor to this research project. An olive-faced M.D., Ph.D., passed through this confusing scene briefly, and when he left, a small supply of DOPR left with him. He promptly published in an obscure journal some animal behavioral responses which he ascribed to the isopropyl analogue, DOIP. But what he had studied could only have been DOPR since DOIP, at that time, had not yet been synthesized either by me, or by either of the other two active synthesists of that moment. It was not yet a known material. We all made it some time later, but by that time our olive-face had disappeared. There is a magnificent French phrase that applies here as nowhere else; Il a foutu le camp. Its idiomatic meaning is equivalent to our, “He took off,” or “He split the scene,” but the literal translation is, “He fucked the camp.”

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About PiHKAL • info

This version of Book II of PiHKAL is based on the Erowid online version, originally transcribed by Simson Garfinkle and converted into HTML by Lamont Granquist. I drew also on “Tyrone Slothrop’s” (Unfinished) Review of PIHKAL to enumerate the many analogues mentioned in PiHKAL but not described at length. Still others remain to be added.

I have tried here to expunge any artifacts introduced by the earlier transcriptions and restore most of the typographic niceties found in the printed edition. 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

“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

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The copyright for Book I of PiHKAL has been reserved in all forms and it may not be distributed. Book II of PiHKAL may be distributed for non-commercial reproduction provided that the introductory information, copyright notice, cautionary notice and ordering information remain attached.

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