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Book II of PiHKAL: A Chemical Love Story, by Alexander & Ann Shulgin #28: 2C-G-3
#28 2C-G-3: 2,5-Dimethoxy-3,4-(trimethylene)phenethylamine

#28 2C-G-3 SYNTHESIS: To a solution of 22 g of KOH in 250 mL of hot EtOH, there was added 50 g of 4-indanol and 75 g methyl iodide. The mixture was held at reflux for 12 h. There was then added an additional 22 g KOH followed by an additional 50 g of methyl iodide. Refluxing was continued for an additional 12 h. The mixture was poured into 1 L H2O, acidified with HCl, and extracted with 3×75 mL CH2Cl2. The pooled extracts were washed with 5% NaOH, then with dilute HCl, and the solvent was removed under vacuum. The residue of crude 2,3-(trimethylene)anisole weighed 56.5 g and was used without further purification in the following reaction.

A mixture of 327 g N-methylformanilide and 295 g POCl3 was allowed to incubate until a deep claret color had formed. To this there was then added 110 g of crude 2,3-(trimethylene)anisole, and the mixture heated on the steam bath. There was a vigorous evolution of gases, which largely quieted down after some 4 h of heating. The reaction mixture was added to 4 L H2O and stirred overnight. The oily aqueous phase was extracted with 3×200 mL CH2Cl2, and after combining the extracts and removal of the solvent there was obtained 147 g of a black, sweet-smelling oil. This was distilled at 182–194 °C at the water pump to yield 109.1 g of a pale yellow oil. At low temperature, this crystallized, but the solids melted again at room temperature. Gas chromatography of this product on OV-17 at 185 °C showed detectable starting anisole and N-methylformanilide (combined, perhaps 5% of the product) and a small but real isomeric peak, (about 5%, slightly faster moving than the title aldehyde, again about 5% of the product) of what was tentatively identified as the ortho-aldehyde (2-methoxy-3,4-(trimethylene)benzaldehyde). The bulk of this crude product (74 g) was redistilled at 110–130 °C at 0.3 mm/Hg to give 66 g of 4-methoxy-2,3-(trimethylene)benzaldehyde as a nearly colorless oil which set up as a crystalline solid. A portion on porous plate showed a mp of 28–29 °C. A gram of this aldehyde and a gram of malononitrile in 25 mL of EtOH was treated with a few drops of triethylamine and gave pale yellow crystals of the malononitrile derivative. This, upon recrystallization from 50 mL boiling EtOH, had a mp of 176–176.5 °C. Anal. (C14H12N2O) C,H,N. A side path, other than towards the intended targets 2C-G-3 and G-3, was explored. Reaction with nitroethane and anhydrous ammonium acetate gave the 2-nitropropene analogue which was obtained in a pure state (mp 74–75 °C from MeOH) only after repeated extraction of the crude isolate with boiling hexane. Reduction with elemental iron gave the phenylacetone analogue which was reductively aminated with dimethylamine and sodium cyanoborohydride to give N,N-dimethyl-4-methoxy-2,3-(trimethylene)amphetamine. This was designed for brain blood-flow volume studies after iodination at the 5-position (N,N-dimethyl-5-iodo-4-methoxy-2,3-(trimethylene)amphetamine), a concept that has been discussed under IDNNA. It has never been tasted by anyone. The corresponding primary amine, 4-methoxy-2,3-(trimethylene)amphetamine has not yet even been synthesized.

A solution of 34.8 g 4-methoxy-2,3-(trimethylene)benzaldehyde in 800 mL CH2Cl2 was treated with 58.6 g of 85% m-chloroperoxybenzoic acid and held at reflux for 3 days. After cooling and standing for a few days, the solids were removed by filtration and washed sparingly with CH2Cl2. The combined filtrate and washings were washed with 200 mL saturated NaHCO3, and the solvent removed, yielding 43.5 g of a deeply colored oil. This was dissolved in 150 mL MeOH to which was added 9 g NaOH and all heated to reflux on the steam bath. After 1 h, a solution of 9 g NaOH in 20 mL H2O was added, heated further, then followed by yet another treatment with 9 g NaOH in 20 mL H2O followed by additional heating. All was added to 800 mL H2O, washed once with CH2Cl2 (which removed a trivial amount of material) and then acidified with HCl. The dark crystals that were generated were filtered and air dried to constant weight, yielding 27.5 g dark but nice-looking crystals with a mp of 89–91 °C. By all counts, this should have been the product phenol, 4-methoxy-2,3-(trimethylene)phenol, but the microanalysis indicated that the formate ester was still there. Anal. (C10H12O2) requires C = 73.08, H = 7.37. (C11H12O3) requires C = 68.73, H = 6.29. Found: C = 69.04, 68.84; H = 6.64, 6.58. Whatever the exact chemical status of the phenolic hydroxyl group might have been, it reacted successfully in the following methylation step.

To a solution of 10 g KOH in 100 g EtOH (containing 5% IPA) there was added 27.5 g of the above 89–91 °C melting material, followed by 25 g methyl iodide. The mixture was held at reflux overnight. All was added to 800 mL H2O, acidified with HCl, and extracted with 3×100 mL CH2Cl2. The combined extracts were washed with 3×100 mL 5% NaOH, then once with dilute HCl, and the solvent removed under vacuum yielding 20.4 g of a fragrant crystalline residue. This was recrystallized from 60 mL boiling MeOH to give, after filtering and air drying, 16.0 g of 1,4-dimethoxy-2,3-(trimethylene)benzene (4,7-dimethoxyindane) with a mp of 86–88 °C. Anal. (C11H14O2) C,H.

To a mixture of 39.0 g of N-methylformanilide and 35.9 g POCl3 that had been allowed to stand at ambient temperature until deeply claret (about 45 min) there was added 15.8 g of 1,4-dimethoxy-2,3-(trimethylene)benzene. The mixture was heated on the steam bath for 4 h and then poured into 600 mL H2O. After stirring overnight there was produced a heavy crystalline mass. This was removed by filtration and, after air drying, was extracted with 3×100 mL boiling hexane. Pooling and cooling these extracts yielded 9.7 g of salmon-colored crystals with a mp of 67–68 °C. This was recrystallized from 25 mL boiling EtOH to give, after filtration, EtOH washing, and air drying to constant weight, 7.4 g of 2,5-dimethoxy-3,4-(trimethylene)benzaldehyde, with a mp of 71–72 °C. The mother liquors on cautious treatment with H2O, yielded, after EtOH recrystallization, 1 g additional product. Anal. (C12H14O3) C,H. A solution of 150 mg aldehyde and an equal weight of malononitrile in 2.3 mL EtOH treated with 3 drops triethylamine gave immediate yellow crystals of the malononitrile derivative, with a mp of 161–162 °C. Anal. (C15H14N2O2) C,H,N.

A solution 3.7 g 2,5-dimethoxy-3,4-(trimethylene)benzaldehyde in 15 g nitromethane was treated with 0.7 g anhydrous ammonium acetate and heated on the steam bath for 14 h. The volatiles were removed under vacuum, and the residue set up to 3.5 g dark crystals, which melted broadly between 126–138 °C. Recrystallization of the entire mass from 70 mL boiling EtOH gave 3.2 g burnished gold crystals with a mp of 129–137 °C. A further recrystallization of an analytical sample from MeOH gave 2,5-dimethoxy-3,4-(trimethylene)-β-nitrostyrene as yellow crystals with a mp of 146–147 °C. Anal. (C13H15NO4) C,H.

To a cold solution of LAH in THF (40 mL of a 1 M solution) well stirred and under an inert atmosphere, there was added dropwise 1.05 mL freshly prepared 100% H2SO4. There was then added, dropwise, a solution of 2.39 g 2,5-dimethoxy-3,4-(trimethylene)-β-nitrostyrene in 25 mL THF. The bright yellow color was discharged immediately. After the addition was complete, stirring was continued for an additional 20 min, and the reaction mixture brought to a reflux on the steam bath for another 0.5 h. After cooling, the excess hydride was destroyed with IPA (8 mL required) followed by sufficient 15% NaOH to convert the inorganics into a loose, filterable mass. This was removed by filtration, and the filter cake washed with THF. The combined filtrate and washes were stripped of solvent under vacuum, and the residue dissolved in dilute H2SO4. After washing with CH2Cl2, the aqueous phase was made basic with 25% NaOH and extracted with 3×75 mL CH2Cl2. After removal of the solvent under vacuum, the residue was distilled at 125–160 °C at 0.45 mm/Hg to yield 0.80 g of a white oil. This was dissolved in 8 mL IPA, neutralized with 20 drops of concentrated HCl (the salt crystals started to form before this was completed) followed with the addition of 65 mL anhydrous Et2O. The white crystalline mass was filtered, washed with Et2O, and air dried to provide 1.16 g of 2,5-dimethoxy-3,4-(trimethylene)phenethylamine hydrochloride (2C-G-3) with a mp of 214–216 °C with decomposition. Anal. (C13H20ClNO2) C,H.

DOSAGE: 16–25 mg.

DURATION: 12–24 h.

QUALITATIVE COMMENTS: (with 16 mg) “It came on in little leaps and bounds. All settled, and then it would take another little jump upwards. I am totally centered, and writing is easy. My appetite is modest. Would I drive to town to return a book to the library? No ever-loving way! I am very content to be right here where I am safe, and stay with the writing. It does take so much time to say what wants to be said, but there is no quick way. A word at a time.”

(with 22 mg) “I walked out for the mail at just about twilight. That was the most courageous thing that I could possibly have done, just for one lousy postcard and a journal. What if I had met someone who had wanted to talk? Towards evening I got a call from Peg who said her bean soup was bubbling in a scary way and what should she do, and I said maybe better make soap. It was that kind of an experience! Way up there, lots of LSD-like sparkles, and nothing quite really making sense. Marvelous.”

(with 25 mg) “There was easy talking, and no hint of any body concern. Sleep that evening was easy, and the next day was with good energy.”

EXTENSIONS AND COMMENTARY: The positives of a completely intriguing altered state free from apparent physical threats, are here coupled with the negative of having to invest such a long period of time. There is a merry nuttiness which can give a joyous intoxication, but with the underlying paranoia of how it looks to others. There is an ease of communication, but only within surroundings that are well-known and friendly. This might be a truly frightening experience if it were in an unfamiliar or unstructured environment.

The numbering of this compound, and all the extensions of GANESHA, have been made on the basis of the nature of the stuff at the 3,4-position. Here there are three atoms (the trimethylene bridge) and so 2C-G-3 seems reasonable. With this logic, the dimethylene bridge would be 2C-G-2 (and the corresponding amphetamine would be G-2, of course). But these compounds call upon a common intermediate which is a benzocyclobutene, OK in principle but not yet OK in practice. The right benzyne reaction will be there someday, and the dimethylene analogues will be made and assayed. But, in the meantime, at least the names have been assigned.

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.

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