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Book II of PiHKAL: A Chemical Love Story, by Alexander & Ann Shulgin #30: 2C-G-5
#30 2C-G-5: 3,6-Dimethoxy-4-(2-aminoethyl)benzonorbornane

#30 2C-G-5 SYNTHESIS: To a stirred solution of 25 g 3,6-dihydroxybenzonorbornane (from Eastman Kodak Company) in 200 mL acetone there was added 200 mg decyltriethylammonium iodide, 40 g of powdered anhydrous K2CO3, and 55 g methyl iodide. The mixture was held at reflux with a heating mantle overnight. After removal of the solvent under vacuum, the residue was added to 2 L of H2O, acidified with concentrated HCl, and extracted with 3×100 mL CH2Cl2. The pooled extracts were washed with 2×150 mL 5% NaOH and once with dilute HCl, and the solvent was removed under vacuum to give 19.0 g of a black oil as a residue. This was distilled at 90–115 °C at 0.3 mm/Hg to yield 15.5 g of an orange oil which set up as a crystalline solid. The product, 3,6-dimethoxybenzonorbornane, had a mp of 35–37 °C from hexane or 40–41 °C from MeOH. Anal. (C13H16O2) C,H.

A solution of 4.6 g POCl3 and 4.6 g N-methylformanilide was heated briefly on the steam-bath until the color had become deep claret. There was then added 3.05 g of 3,6-dimethoxybenzonorbornane and the solution was heated on the steam bath for 12 h. The black, tarry reaction mixture was poured into H2O, and after hydrolysis, the H2O was decanted and the insoluble residues were washed alternately with H2O and with CH2Cl2. The combined washes were separated, and the aqueous phase extracted with 2×50 mL CH2Cl2. The combined organic fractions were washed with 5% NaOH, and the solvent removed under vacuum. The fluid, black residue was distilled at 130–140 °C at 0.3 mm/Hg to give 1.17 g of an almost white oil. This was dissolved in 1 mL MeOH, and cooled to -50 °C to give a white crystalline solid that was removed by filtration and washed sparingly with -50 °C MeOH and air dried. There was obtained 0.83 g 3,6-dimethoxy-4-formylbenzonorbornane with a mp of 37–40 °C which could be increased, by wasteful recrystallization from MeOH, to 53–54 °C. An intimate mixture of this product with the starting diether (mp 40–41 °C) was a liquid at room temperature. Anal. (C14H16O3) C,H.

To a solution of 3.70 g 3,6-dimethoxy-4-formylbenzonorbornane in 20 g nitromethane, there was added 1.3 g anhydrous ammonium acetate and the mixture was heated on the steam bath for 45 min. The excess reagent/solvent was removed under vacuum, and the residue was dissolved in 20 mL boiling MeOH. A speck of seed crystal started a heavy crystallization of orange crystals which were removed by filtration and washed with MeOH. After drying, the product 3,6-dimethoxy-4-(2-nitrovinyl)benzonorbornane was yellow, weighed 3.47 g, and had a mp of 88–89 °C. Recrystallization of an analytical sample from MeOH did not improve this mp. Anal. (C15H17NO4) C,H.

A solution of LAH (46 mL of a 1 M solution in THF) was cooled, under He, to 0 °C with an external ice bath. With good stirring there was added 1.25 mL 100% H2SO4 dropwise, to minimize charring. This was followed by the addition of 3.4 g 3,6-dimethoxy-4-(2-nitrovinyl)benzonorbornane in 30 mL anhydrous THF. After a few min further stirring, the temperature was brought up to a gentle reflux on the steam bath for 10 min, and then all was cooled again to 0 °C. The excess hydride was destroyed by the cautious addition of 7 mL IPA, followed by 2 mL 15% NaOH and 5 mL H2O, which gave an easily filtered white granular solid. This was removed by filtration, and the filter cake was washed with THF. The combined filtrate and washes were stripped of solvent under vacuum providing a pale amber oil which was distilled at 150–160 °C at 0.3 mm/Hg to give 1.45 g of a white oil. This was dissolved in 7 mL IPA, and neutralized with 15 drops of concentrated HCl. There was then added 25 mL anhydrous Et2O and, after a short delay, white crystals formed spontaneously. These were removed by filtration, Et2O washed, and air dried to constant weight, yielding 1.13 g of 3,6-dimethoxy-4-(2-aminoethyl)benzonorbornane hydrochloride (2C-G-5). The mp was 199–200 °C. Anal. (C15H22ClNO2) C,H.

DOSAGE: 10–16 mg.

DURATION: 32–48 h.

QUALITATIVE COMMENTS: (with 14 mg) “I was well aware of things at the end of two hours, and I was totally unwilling to drive, or even go out of the house. I was reminded continuously of 2C-B with its erotic push, and the benign interplay of colors and other visual effects. But it is so much longer lived. I am a full +++, very stoned, and there is no believable sign of dropping for another several hours. There is a good appetite (again, 2C-B like), and I managed to sleep for a few hours, and all the next day I was spacey and probably still a plus one. The day yet following, I was finally at a believable baseline. Both of these days were filled with what might be called micro doze-offs, almost like narcolepsy. Maybe I am just sleep deprived.”

(with 16 mg) “The first effects were felt within one hour, and full effects between 2 1/2 and 3 hours. Tremendous clarity of thought, cosmic but grounded, as it were. This is not at all like LSD, and is a lot mellower than the 2C-T family. For the next few hours it was delightful and fun and I felt safe and good-humored. I got to sleep without much difficulty while still at a plus three, and my dreams were positive and balanced, but I awoke irritable and emotionally flattened. I did not want to interact with anyone. The first 16 hours of this stuff were great, and the second 16 hours were a bit of a drag. Just twice as long as it ought to be.”

(with 16 mg) “I was at full sparkle within three hours, and I continued to sparkle for the longest time. The tiredness that comes after a while probably reflects the inadequacy of sleep. I was aware of something still going on some two days later.”

EXTENSIONS AND COMMENTARY: In the eventual potency assessment of a drug, there must be some consideration of not only the dosage needed, but the duration of effects. The area under the curve, so to speak. By these measures, this phenethylamine is a record breaker, in that it is not only amongst the most potent, but it goes on and on and on.

There are a couple of chemical commentaries. One, the miserable phenol-to-ether-to-aldehyde series of steps, so maddeningly unsatisfactory in the 2C-G-4 process, was completely comfortable here. The reactions rolled, and the yields were most satisfactory. Secondly, this is one of the few phenethylamines that is a racemate. The strange geometry of the norbornane ring carries within it a chiral character, so this compound is potentially resolvable into two optically active forms. That might be quite a task, but it would have the value of providing for the first time a pair of isomers that were asymmetric in the 3,4-aliphatic part of the molecule. To the extent that some insight into the geometry of the receptor site can be gleaned from the absolute configurations of active agonists, here is a compound where the subtle variations are over there at the ring substitution area of the structure, rather than at the well-explored alpha-carbon atom. Some day I might try to resolve this drug into its optical isomers. But I suspect that it might be quite difficult.

A number of chemical variations of 2C-G-5 are obvious. The dihydroxybenzonorbornane compound that was the starting point of all this was certainly the adduct of cyclopentadiene and benzoquinone, with the double bond reduced. The same chemistry with 1,3-cyclohexadiene would give a two-carbon bridge instead of the one-carbon bridge of norbornane and, after hydrogenation, would provide a non-chiral analog with two ethylene bridges between the 3- and 4-position carbons. This is a cyclohexane ring connected, by its 1- and 4-positions, to the two methyl groups of 2C-G. With six carbons in this aliphatic mess, the compound is probably best called 2C-G-6. It should be easily made, and it is certain to be very potent. And there are potentially several other Diels Alder dienes that might serve with benzoquinone as the dieneophile. There are aliphatic things such as hexa-2,4-diene and 2,3-dimethylbutadiene. The textbooks are filled with dozens of diene candidates, and benzquinone will always provide the two oxygens needed for the eventual 2,5-dimethoxy groups of the phenethylamine.

Page updated 30 March 2012 · This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License ·

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

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.

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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.

Although 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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