Pihkal

by Alexander Shulgin

  This admonition applies to all the published M.U. values that are preceded by the Rless thanS sign, the R<.

  160 TMA-4; 2,3,5-TRIMETHOXYAMPHETAMINE

  SYNTHESIS: To a solution of 68 g 2,4-dimethoxybenzaldehyde in 250 mL

  glacial acetic acid that had been warmed to 25 !C and well stirred, there was added, dropwise, 86 g of a 40% peracetic acid solution (in acetic acid). The reaction was exothermic, and the rate of addition was dictated by the need to maintain the internal temperature within a few degrees of 28 !C. External cooling was used as needed. The addition took 1 h, and when the reaction had clearly been completed (no further temperature rise) the entire reaction mixture was added to 3 volumes of H2O. The excess acid was neutralized with solid K2CO3

  (283 g were required). This was extracted with 3x100 mL Et2O, the extracts pooled, and stripped of solvent under vacuum to give 66 g of crude 2,4-dimethoxyphenyl formate. This was suspended in 125 mL 10%

  NaOH, and the mixture heated on the steam bath for 1.5 h. On cooling, the reaction mixture set to a heavy black solid. This was removed by filtration, washed with H2O, and dissolved in 250 mL CH2Cl2. The organic phase was washed with dilute HCl, and then with aqueous NaHCO3, which removed much of the color. Removal of the solvent under vacuum gave a deep red goo that was dissolved in 200 mL anhydrous Et2O

  and filtered through paper. The resulting clear solution was stripped of solvent, yielding 34.4 g of 2,4-dimethoxyphenol as a red oil that crystallized on cooling. A 1.0 g sample in 4 mL pyridine was treated with 0.9 g benzoyl chloride and heated on the steam bath for a few min. The addition of H2O gave a pasty solid that was isolated by pressing on a porous plate. The yield of crude 2,4-dimethoxyphenyl benzoate was 1.1 g. Recrystallization from cyclohexane gave a white product with a mp of 86-87 !C. A second recrystallization from cyclohexane raised this to 89-90 !C, which is in agreement with the literature value.

  To a solution of 31.0 g crude 2,4-dimethoxyphenol in 60 mL absolute EtOH there was added a solution of 11.25 g KOH in 90 mL boiling EtOH.

  To this, there was then added 28 g allyl bromide which produced an immediate white precipitate of KBr. The mixture was held at reflux for 2 h and then quenched in 3 volumes of H2O. Sufficient 10% NaOH

  was added to make the reaction strongly basic, and this was extracted with 3x100 mL Et2O. Removal of the solvent under vacuum gave 33.2 g of 1-allyloxy-2,4-dimethoxybenzene, shown to be free of phenol starting material by GC analysis. Analyses must be carried out at low column temperatures (below 180 !C) on an ethylene glycol succinate substrate. If a silicone column is used, even at these low temperatures, there is considerable Claisen rearrangement taking place on the column. Low temperature distillation can be used for further purification (107-110 !C at 1.0 mm/Hg).

  A 31.0 g sample of 1-allyloxy-2,4-dimethoxybenzene was gently heated with a soft flame until the internal temperature reached 215 !C. An exothermic reaction took place, with the temperature rising to 270 !C.

  The residue left in the flask was largely 2-allyl-4,6-dimethoxyphenol, that contained perhaps 10% of 2,4-dimethoxyphenol which resulted from the pyrolytic loss of the allyl group. This mixture was methylated without further purification.

  To a solution of 30 g impure 2-allyl-4,6-dimethoxyphenol in a little absolute EtOH there was added a boiling solution of 8.7 g KOH in 75 mL

  absolute EtOH followed, immediately, by 22.4 g methyl iodide in a little EtOH. The mixture was held at reflux for 3 h, then added to 4

  volumes of H2O. Sufficient 10% NaOH was added to make the mixture strongly basic, and this was extracted with 4x100 mL Et2O. Removal of the solvent gave 28 g of 1-allyl-2,3,5-trimethoxybenzene. GC analysis showed some 10% of the expected impurity, 1,2,4-trimethoxybenzene.

  To a solution of 26 g crude 1-allyl-2,3,5-trimethoxybenzene in an equal weight of absolute EtOH there was added 52 g of flaked KOH. The mixture was heated on the steam bath overnight, and then quenched with much H2O. This was extracted with 3x100 mL Et2O which, on removal under vacuum gave 24.6 g of product. This contained, by GC analysis, largely cis- and trans-1-propenyl-2,3,5-trimethoxybenzene and the expected 1,2,4-trimethoxybenzene. This mixture was dissolved in an equal volume of pentane, and cooled in dry ice. Quick filtration gave 9.2 g of an amber solid which had a melting point of 39-41.5 !C.

  Recrystallization from hexane provided pure trans-1-propenyl-2,3,5-trimethoxybenzene with a mp of 44-45 !C.

  Evaporation of the original pentane mother liquor provided an impure sample of mixed cis- and trans- isomers.

  A solution of 7.2 g trans-1-propenyl-2,3,5-trimethoxybenzene in 41 g dry acetone was treated with 3.3 g dry pyridine and, with good stirring, cooled to 0 !C. There was then added 6.9 g of tetranitromethane over the course of 1 min, and the reaction mixture was allowed to stir for an additional 2 min. The reaction mixture was then quenched with a solution of 2.2 g KOH in 40 mL H2O. After the addition of more H2O, the product was extracted with 3x50 mL CH2Cl2.

  Removal of the solvent under vacuum yielded 7.0 g of an impure product which would not crystallize. This was distilled under vacuum to give four fractions, all of which crys-tallized spontaneously. Cuts #1 and #2 (bp 100-120 !C and 120-130 !C at 2 mm/Hg) were combined, weighed 0.8 g, and after crystallization from hexane yielded white crystals with a mp of 62-63 !C. The NMR spectrum (in CDCl3) was in agreement with 2,3,5-trimethoxybenzaldehyde, and the literature mp has been reported as being 62-63 !C. Cuts #3 and #4 (bp 130-170 !C and 170-175

  !C at 2 mm/Hg with the bulk coming over in the latter fraction) were combined to give 3.0 g of yellow crystals. These were triturated under a little cold MeOH, and then recrystallized from MeOH to give 1.15 g of yellow crystals of

  2-nitro-1-(2,3,5-trimethoxyphenyl)propene, with a mp of 87-88 !C. The forerun of the distillation contained considerable unreacted trans-1-propenyl-2,3,5-trimethoxybenzene and some 1,2,4-trimethoxybenzene, by GC analysis.

  To a refluxing and stirred suspension of 1.1 g LAH in 150 mL anhydrous Et2O and under an inert atmosphere, there was added a solution of 1.1

  g 2-nitro-1-(2,3,5-trimethoxyphenyl)propene in 50 mL anhydrous Et2O.

  The creamy mixture was held at reflux for 4 h, cooled, and then the excess hydride cautiously destroyed by the addition of 1.5 N H2SO4.

  There was then added 20 g potassium sodium tartrate followed by sufficient aqueous NaOH to raise the pH to >9. The Et2O phase was separated, and the remaining aqueous phase extracted with 3x75 mL

  CH2Cl2. The organic phase and extracts were combined, and the solvent removed under vacuum yielding 0.9 g of a colorless oil. This was dissolved in 200 mL anhydrous Et2O which was saturated with anhydrous HCl gas. There was generated a thick oil that did not crystallize.

  The Et2O was decanted from this, and allowed to stand for several days in a sealed container at room temperature. There was the deposition of fine white needles of 2,3,5-trimethoxyamphetamine hydrochloride (TMA-4) weighing, after Et2O washing and air drying, 0.31 g. The mp was 118-119 !C. Anal. (C12H20ClNO3) C,H. The residual oil was dissolved in H2O, made basic with NaOH, and extracted with CH2Cl2.

  Evaporation of the solvent gave 0.40 of a white oil which was dissolved in a little MeOH containing 0.22 g oxalic acid. There was the immediate deposition of crystals of the oxalate salt of 2,3,5-trimethoxyamphetamine, with a mp of about 110 !C.

  DOSAGE: greater than 80 mg.

  DURATION: perhaps 6 h.

  QUALITATIVE COMMENTS: (with 80 mg) I was concerned about life issues, with much introspection, for about 6 hours. There were no subjective physical symptoms. It was comparable to about 50 micrograms of LSD, or to 120 milligrams TMA, for me.

  EXTENSIONS AND COMMENTARY: That is the sum total of the knowledge of subjective effects that exist. There was such a precious small amount of the final hydrochloride salt that, by the time the needed build-up of dosage had been completed, there was just enough left for this single trial, which was conducted in South America. Based upon the volunteered comparisons to LSD and TMA, a potency for this compound has be
en published that states that it is 4x the potency of mescaline, or 4 M.U. The material must be re-synthesized, and re-evaluated with the now-accepted protocol.

  In the future re-synthesis, there will be a considerable improvement made with the several steps that are described above. The products from the preparations of the phenol, the allyl ether, the Claisen rearrangement, the methylation of the new phenol, and the isomerization to the mixture of cis- and trans-propenylbenzenes were all conducted without the benefit of a Kugel-Rohr apparatus. The products became progressively thick and blacker, and it was only by the grace of getting a solid at the trans-propenyl stage that some degree of purity could finally be obtained. All of the intermediates are certainly white oils, and when this preparation is repeated, they will be distilled at each and every stage.

  This 2,3,5-orientation of the methoxy groups on the aromatic ring is far and away the most difficult tri-substitution pattern known to chemists. There just isnUt any simple way to put it together. The 2-carbon phenethylamine (2,3,5-trimethoxyphenethylamine) had been synthesized quite a while ago. Its role as a substrate for liver amine oxidase in in vitro studies has been explored, but it has never been tried in man. Even more bizarre is the amphetamine with this oxygenation pattern, in which a methylenedioxy ring has replaced the two adjacent methoxyl groups. This is the material 2,3-methylenedioxy-5-methoxyamphetamine, or MMDA-4. Despite its theoretical appeal (being one of the six possible MMDA derivatives) and it's synthetic challenge (as with the 2,3,5-trimethoxy things above, everything is simply in the wrong position) the compound is of unknown pharmacology. This follows, quite logically, from the fact that it has never been synthesized. No one has yet put together a workable procedure that would make it. In the course of making all possible positional isomers of MMDA explicitly Schedule I drugs, the DEA has named this compound, and since it was specifically named, it was entered into the Chemical Abstracts. So it is listed in the literature, at least it is in the Chem. Abstracts. But it is in reality completely unknown. Some day, some one somewhere will have a light bulb go on over his head, and find a synthetic process that will make it. Of course, the moment it is made, an illegal act will have occurred, at least in the United States as long as the present laws remain unchanged, as it is currently a Schedule I drug.

  Needless to say, the 2-carbon analog of MMDA-4, 2,3-methylenedioxy-5-methoxyphenethylamine (would 2C-MMDA-4 be a reasonable name?) is also unknown.

  161 TMA-5; 2,3,6-TRIMETHOXYAMPHETAMINE

  SYNTHESIS: A solution of 100 g 1,2,4-trimethoxybenzene in 1 L hexane was cooled to 15 !C and treated with 400 mL of a 15% solution of n-butyllithium in hexane. A white precipitate formed immediately, and stirring was continued for an additional 2 h while the reaction returned to room temperature. There was then added a solution of 40 g freshly distilled propionaldehyde in 100 mL hexane. The reaction was exothermic and, as the stirring was continued, the precipitate gradually dissolved. Stirring was continued overnight at room temperature. There was then added 1 L H2O, and the reaction was acidified with HCl. The hexane phase was separated, and the remaining aqueous phase was extracted with hexane, then with Et2O. The pooled organic extracts were stripped of solvent under vacuum, and the residue distilled to give 60 g ethyl 2,3,6-trimethoxyphenyl carbinol, with an index of refraction nD20 = 1.5192. Anal. (C12H18O4) C,H.

  From the Et2O extracts above, additional carbinol was obtained, containing a small amount of the starting 1,2,4-trimethoxybenzene.

  The two materials were readily separated by vacuum distillation, providing an additional 21 g of carbinol.

  The above alcohol, 60 g of ethyl 2,3,6-trimethoxyphenyl carbinol, was stirred without solvent and cooled to 0 !C with an external ice bath.

  There was then added 80 g PBr3 at a rate that maintained the temperature below 60 !C. At the end of the addition, there were added quantities of chipped ice, followed by H2O. The reaction mixture was extracted with 3x100 mL Et2O, and removal of the solvent provided 60 g of 1-bromo-1-(2,3,6-trimethoxyphenyl)propane which was used in the following dehydrobromination step without further purification.

  A solution of the above 60 g of

  1-bromo-1-(2,3,6-trimethoxyphenyl)propane in an equal weight of EtOH

  was treated with 120 g of flaked KOH. The exothermic reaction was allowed to run its course with stirring continued overnight. The mixture was then quenched in H2O and extracted with 3x200 mL CH2Cl2.

  Removal of the solvent from the pooled extracts gave a crude product which contained no starting bromo material, but which was contaminated with an appreciable quantity of the ethoxy analogue, 1-ethoxy-1-(2,3,6-trimethoxyphenyl)propane. This impure product was heated briefly to 80 !C with 50% H2SO4. Cooling, dilution with water, and re-extraction with 3x100 mL CH2Cl2 gave, after removal of the volatiles under vacuum, 1-(2,3,6-trimethoxyphenyl)propene. This was distilled to provide 7.0 g of a clear oil that was a 12:1 ratio of the trans- and cis-isomers.

  A well-stirred solution of 6.8 g of the mixed isomers of 1-(2,3,6-trimethoxyphenyl)propene in 40 g of dry acetone was treated with 3.2 g pyridine and cooled to 0 !C with an external ice bath.

  There was then added 6.5 g tetranitromethane over the course of 1 min, the stirring was continued for an additional 2 min, and then the reaction mixture was quenched by the addition of 2.2 g KOH in 40 mL

  H2O. There was additional H2O added, and the organics were extracted with 3x75 mL CH2Cl2. The solvent from the pooled extracts was removed under vacuum, and the 5.3 g residue distilled at 0.2 mm/Hg. A fraction boiling at 150-170 !C proved to be largely 2,3,6-trimethoxybenzaldehyde. A second fraction (170-200 !C at 0.2

  mm/Hg) also spontaneously crystallized to a yellow solid. This was recrystallized from MeOH to provide, after drying to constant weight, 2.8 g of 2-nitro-1-(2,3,6-trimethoxyphenyl)propene with a mp of 73-74

  !C. Anal. (C12H15NO5) C,H.

  To a refluxing and stirred suspension of 2.4 g LAH in 300 mL anhydrous Et2O and under an inert atmosphere, there was added a solution of 2.4

  g 2-nitro-1-(2,3,6-trimethoxyphenyl)propene in 100 mL anhydrous Et2O.

  The mixture was held at reflux for 4 h, cooled, and then the excess hydride cautiously destroyed by the addition of 1.5 N H2SO4. There was then added 40 g potassium sodium tartrate followed by sufficient aqueous NaOH to raise the pH to >9. The Et2O phase was separated, and the remaining aqueous phase extracted with 3x100 mL CH2Cl2. The organic phase and extracts were combined, and the solvent removed under vacuum yielding 1.8 g of a colorless oil. This was dissolved in 200 mL anhydrous Et2O which was saturated with anhydrous HCl gas.

  There was generated a thick oil that slowly crystallized. The resulting white crystalline solid was removed by filtration, providing 2.2 g 2,3,6-trimethoxyamphetamine hydrochloride (TMA-5). The mp was 124-125 !C. Anal. (C12H20ClNO3) C,H.

  DOSAGE: 30 mg or more.

  DURATION: 8 - 10 h.

  QUALITATIVE COMMENTS: (with 20 mg) There appeared to be a slight stimulation. Modest eye dilation, but normal pulse. If this is the marginal edge of intoxication, then it is not a psychotomimetic, but a stimulant. Go up with care.

  (with 30 mg) Intense introspection. Comparable to about 75

  micrograms of LSD, or more.

  EXTENSIONS AND COMMENTARY: TMA-5, as was the case with TMA-4, has only been superficially explored. The above two quotations are from two different people, and together no more than hint at the possibility that it might be active in the several tens of milligrams.

  Pharmacologists have developed quite an art in the design and evaluation of animal behavior models for the study of psychedelic drugs. They have always faced two formidable tasks, however. There is the qualitative question: is the drug a psychedelic? And there is the quantitative question: how potent is it?

  The first question is addressed by taking a number of known psychedelic drugs, and searching for some animal responses that are common to all. Since there is little logic in the argument that animals can experience, let alone reveal, altered states of consciousness or
fantasy fugues or colored imagery, the investigator must look for objective signs such as conditioned responses to stimuli, or unusual behavior. If one explores ten drugs that are known psychedelics, and all ten produce, say, bizarre nest-building behavior in mice, and an eleventh drug of unknown pharmacology does exactly the same thing, then the eleventh drug can be suspected of being a psychedelic drug.

  And the second question, how potent, is answered by seeing how much of the drug is required to evoke this standardized behavior. This is called the dose-response curve, in which the more drug you give, the more response you get. This curve gives confidence that the drug is indeed responsible for the activity that is seen, as well as giving a quantitative measure of that activity.

  But this entire discipline depends on the acceptance of the fact that the first ten drugs are indeed psychedelic materials. And these inputs can only come from human trials. What is the validity of these assumptions with TMA-5? Not very good. The statement that it is psychedelic has actually been published in reviews solely on the basis of the above two studies; the potency has been put at some ten times that of mescaline. Mescaline is certainly an effective psychedelic drug in the 300-500 milligram range, and this factor of ten implies that TMA-5 is also a psychedelic drug and is active in the 30-50

  milligram range. And indeed, both statements may be true, but confidence in these conclusions must await more extensive trials.

  The two-carbon analogue of TMA-5 is 2,3,6-trimethoxyphenethylamine (or 2C-TMA-5 or 2,3,6-TMPEA). This is a known material, although there has been some controversy as to its physical properties. It has been studied in monoamine oxidase systems, and appears to be either a competitive substrate or an inhibitor of that enzyme. But as far as I know, no one has nibbled it, so its human activity is unknown.