2,5-Dimethoxy-4-chlorophenethylamine
#22 2C-C SYNTHESIS: (from ) The free base of 2,5-dimethoxyphenethylamine was generated from its salt (see recipe for 2C-H for the preparation of this compound) by treating a solution of 16.2 g of the hydrochloride salt in 300 mL H2O with aqueous NaOH, extraction with 3×75 mL CH2Cl2, and removal of the solvent from the pooled extracts under vacuum. The colorless residue was dissolved in 75 mL glacial acetic acid (the solids that initially formed redissolved completely) and this was cooled to 0 °C with an external ice bath. With vigorous stirring, there was added 4.0 mL of liquid chlorine, a little bit at a time with a Pasteur pipette. The theoretical volume was 3.4 mL, but some was lost in pipetting, some on contact with the 0 °C acetic acid, and some was lost by chlorination of the acetic acid. The reaction turned a dark amber color, was allowed to stir for an additional 10 min, then quenched with 400 mL H2O. This was washed with 3×100 mL CH2Cl2 (which removed some of the color) then brought to neutrality with dilute aqueous NaOH and treated with a small amount of sodium dithionite which discharged most of the color (from deep brown to pale yellow). The reaction was made strongly basic with aqueous KOH, and extracted with 3×75 mL CH2Cl2. The pooled extracts were washed once with H2O and the solvent was removed under vacuum leaving about 10 mL of a deep amber oil as residue. This was dissolved in 75 mL IPA and neutralized with concentrated HCl which allowed spontaneous crystallization. These crystals were removed by filtration, washed with an additional 20 mL IPA, and air-dried to constant weight. There was thus obtained 4.2 g 2,5-dimethoxy-4-chlorophenethylamine hydrochloride (2C-C) with a mp of 218–221 °C. Recrystallization from IPA increased this to 220–222 °C. The position of chlorination on the aromatic ring was verified by the presence of two para-protons in the NMR, at 7.12 and 7.20 ppm from external TMS, in a D2O solution of the hydrochloride salt.
Synthesis from . To a solution of 7.24 g 2,5-dimethoxy-4-bromophenethylamine (2C-B) and 4.5 g phthalic anhydride in 100 mL anhydrous DMF there was added molecular sieves. After 16 h reflux, the reaction mixture was cooled and the sieves removed by filtration. The addition of a little CH2Cl2 prompted the deposition of yellow crystals which were recrystallized from EtOH. The resulting 1-(2,5-dimethoxy-4-bromophenyl)-2-(phthalimido)ethane weighed 7.57 g and had a mp of 141–142 °C. Anal. (C18H16BrNO4) C,H,N,Br.
A solution of 14.94 g of 1-(2,5-dimethoxy-4-bromophenyl)-2-(phthalimido)ethane and 4.5 g cuprous chloride in 300 mL anhydrous DMF was heated for 5 h at reflux. The cooled mixture was poured into 20 mL H2O that contained 13 g hydrated ferric chloride and 3 mL concentrated HCl. The mixture was maintained at about 70 °C for 20 min, and then extracted with CH2Cl2. After washing the pooled organic extracts with dilute HCl and drying with anhydrous MgSO4, the volatiles were removed under vacuum to provide a solid residue. This was recrystallized from EtOH to provide 12.18 g of 1-(2,5-dimethoxy-4-chlorophenyl)-2-(phthalimido)ethane as yellow needles that had a mp of 138–140 °C. Anal. (C18H16ClNO4) C,H,N,Cl.
To 60 mL absolute EtOH there was added 12.2 g 1-(2,5-dimethoxy-4-chlorophenyl)-2-(phthalimido)ethane and 2.9 mL of 100% hydrazine. The solution was held at reflux for 15 min. After cooling, the cyclic hydrazone by-product was removed by filtration, and the alcoholic mother liquors taken to dryness under vacuum. The residue was distilled at 145–155 °C at 0.05 mm/Hg to give 5.16 g of a clear, colorless oil. This was dissolved in anhydrous Et2O and treated with hydrogen chloride gas, producing 2,5-dimethoxy-4-chlorophenethylamine hydrochloride (2C-C) as white crystals with a mp of 220–221 °C. Anal. (C10H15Cl2NO2) C,H,N.
DOSAGE: 20–40 mg.
DURATION: 4–8 h.
QUALITATIVE COMMENTS: (with 20 mg) “This is longer lived than , and there is a longer latency in coming on. It took an hour and a half, or even two hours to get there. It had a slight metallic overtone.”
(with 24 mg) “I was at a moderately high and thoroughly favorable place, for several hours. It seemed to be a very sensual place, but without too much in the way of visual distraction.”
(with 40 mg) “There were a lot of visuals—something that I had noted at lower levels. There seems to be less stimulation than with , and in some ways it is actually sedating. And yet I was up all night. It was like a very intense form of relaxation.”
EXTENSIONS AND COMMENTARY: Other reports mention usage of up to 50 milligrams which seems to increase yet further the intensity and the duration. I have one report of an intravenous administration of 20 milligrams, and the response was described as overwhelming. The effects peaked at about 5 minutes and lasted for perhaps 15 minutes.
The halogens represent a small group of atoms that are unique for a couple of reasons. They are all located in a single column of the periodic table, being monovalent and negative. That means that they can be reasonably stable things when attached to an aromatic nucleus. But, being monovalent, they cannot be modified or extended in any way. Thus, they are kind of a dead end, at least as far as the 2C-X series is considered. The heaviest, iodine, was explored as the phenethylamine, as , and as the amphetamine as . These are the most potent. The next lighter is bromine, where the phenethylamine is and the amphetamine is . These two are a bit less potent, and are by far the most broadly explored of all the halides. Here, in the above recipe, we have the chlorine counterpart, 2C-C. There is also the corresponding amphetamine . These are less potent still, and much less explored. Why? Perhaps because chlorine is a gas and troublesome to handle (bromine is a liquid, and iodine is a solid). The fluorine analogue is yet harder to make, and requires procedures that are indirect, because fluorine (the lightest of all the halides) is not only a gas, but is dangerous to handle and does not react in the usual halogen way. There will be mention made of , but is still unexplored.
The treatment of the 2C-B phthalimide described above, with cuprous cyanide rather than cuprous chloride, gave rise to the cyano analog which, on hydrolysis with hydrazine, yielded 2,5-dimethoxy-4-cyanophenethylamine (). Hydrolysis of this with hot, strong base gave the corresponding acid, 2,5-dimethoxy-4-carboxyphenethylamine, . No evaluation of either of these compounds has been made in the human animal, as far as I know.
13 May 2016 · Creative Commons BY-NC-SA ·

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. Many, many others have since been added.
I have tried here to expunge any artifacts introduced by the earlier transcriptions and restore the typographic niceties found in the printed edition. I’ve also made minor changes to some chemical names in line with current nomenclature practice. Typically the change is little more than expanding a prefix or setting it in italics. The history 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

Copyright notice

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.

Ordering information

PiHKAL is the extraordinary record of the authors’ years exploring the chemistry and transformational power of phenethylamines. This book belongs in the library of anyone seeking a rational, enlightened and candid perspective on psychedelic drugs.
Though Sasha and Ann have put Book II of PiHKAL 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.
PiHKAL (ISBN 0-9630096-0-5) is available for US$24.50 (plus $10 domestic first-class shipping) from Transform Press.
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