|[3D .mol structure]|
SYNTHESIS: A stirred solution of 8.3 g 3,5-dimethoxy-1-chlorobenzene and 7.2 g isopropylsulfide in 100 mL anhydrous Et2O was cooled with an external ice bath, and then treated with 67 mL 1.5 M lithium diisopropylamide in hexane which was added over the course of 10 min. The reaction mixture was allowed to return to room temperature and the stirring was continued for 0.5 h. The mixture was poured into dilute H2SO4, the organic layer was separated, and the aqueous phase extracted with 3x75 mL EtOAc. The organic phases were combined, dried over anhydrous K2CO3, and the solvent removed under vacuum. The resulting 4.54 g of almost colorless oil was distilled at 85-95 °C at 0.1 mm/Hg to give 4.2 g of 3,5-dimethoxyphenyl isopropyl sulfide as a colorless oil, showing a single spot on TLC with no indication of starting chlorobenzene. The product formed a picrate salt, but this had an unsatisfactory mp character (partly melting at 45-47 °C, and then completely at about 80-90 °C). The microanalysis for this picrate was low in the carbon value, although the hydrogen and nitrogen were excellent. Anal. (C17H19N3O9S) H,N; C: calcd, 46.25; found, 44.58, 44.45.
To a well-stirred solution of 4.1 g 3,5-dimethoxyphenyl isopropyl sulfide and 3.5 mL N,N,N',N'-tetramethylethylenediamine in 25 mL anhydrous Et2O that had been cooled to -78 °C with a dry-ice/acetone bath, there was added 10 mL 2.5 M hexane solution of butyllithium. The mixture was allowed to return to room temperature, and there was added 3.5 mL DMF which caused the yellow color to progressively darken. The reaction mixture was poured into dilute H2SO4, the Et2O layer was separated, and the aqueous phase extracted with 3x75 mL EtOAc. The solvent was removed from the combined organic phases, and the residue distilled at 0.15 mm/Hg to give two fractions. One, boiling at 120-140 °C, was 0.98 g of a pale yellow mobile liquid, which was part starting sulfide and part product aldehyde by TLC. The second cut, boiling at 160-180 °C, was a viscous liquid, weighed 1.66 g, and was largely 2,6-dimethoxy-4-(i-propylthio)benzaldehyde. This formed a crystalline anil with 4-methoxyaniline (by fusing equimolar amounts of the two with a flame) which, after recrystallization from MeOH, gave fine yellow crystals with a mp of 87.5-89 °C. Anal. (C19H23NO3S) C,H.
A solution of 0.8 g 2,6-dimethoxy-4-(i-propylthio)benzaldehde in 10 mL nitromethane was treated with 0.2 g anhydrous ammonium acetate and heated on the steam bath for 1 h. The excess reagent/solvent was removed under vacuum, and the residue spontaneously solidified. This was recrystallized from 5 mL MeOH to give 0.70 g 2,6-dimethoxy-beta-nitro-4-(i)-propylthiostyrene as a pale yellow fluffy solid, with a mp of 83-84.5 °C. Anal. (C13H17NO4S) C,H.
A solution of LAH (20 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 0.54 mL 100% H2SO4 dropwise, to minimize charring. This was followed by the addition of 0.54 g 2,6-dimethoxy-beta-nitro-4-(i)-propylthiostyrene in a small volume of anhydrous THF. The color was discharged immediately. After a few minutes further stirring, the temperature was brought up to a gentle reflux on the steam bath for about 10 min, and then all was cooled again to 0 °C. The excess hydride was destroyed by the cautious addition of IPA followed by sufficent 15% NaOH to give a white granular character to the oxides, and to assure that the reaction mixture was basic. The reaction mixture was filtered, and the filter cake washed well with THF. The filtrate was stripped of solvent under vacuum and the residue dissolved in 100 mL of dilute H2SO4. This was washed with 2x50 mL CH2Cl2 (the washes were saved, see below), made basic with aqueous NaOH, and then extracted with 2x50 mL CH2Cl2. The residue remaining after the removal of the solvent was distilled at 130-140 °C at 0.05 mm/Hg to give 0.11 g of a white oil. This was dissolved in 10 mL IPA, neutralized with 5 drops of concentrated HCl and diluted with 50 mL anhydrous Et2O. After filtration of the formed crystals, Et2O washing, and air drying, there was obtained 80 mg of 2,6-dimethoxy-4-(i)-propylthiophenethylamine hydrochloride (psi-2C-T-4) as fine white crystals. The removal of the solvent from the CH2Cl2 washes of the dilute H2SO4 solution gave a H2O-soluble white solid that proved to be the sulfate salt of the product. This provided, after making the H2O solution basic, extraction with CH2Cl2, and solvent removal, the free base that was converted, as described above, to a second crop of the hydrochloride salt.
DOSAGE: above 12 mg.
DURATION: probably short.
QUALITATIVE COMMENTS: (with 8 mg) I might actually be up to a plus 1, and with a very good feeling. But I cannot say how long it lasted, and it was probably pretty short. It just sort of faded away.
(with 12 mg) At the 25 minute point I am reminded of the experiment, and in another quarter hour I am into something. Will this be another forever threshold? I feel very good, but there is no sparkle.
EXTENSIONS AND COMMENTARY: Here is another example of the presentation of a compound for which there has not yet been an effective level determined. Why? For a very good reason. This is an example of a whole class of compounds that I have called the pseudos, or the psi-compounds. Pseudo- as a prefix in the literary world generally stands for "false." A pseudopod is a thing that looks like a foot, but isn't one. A pseudonym is a fictitious name. But in chemistry, it has quite a different meaning. If something has a common name, and there is a second form (or isomer, or shape, or orientation) that is possible and it doesn't have a common name, it can be given the name of the first form with a Rpseudo-S attached. Ephedrine is the erythro-isomer of N-methyl-beta-hydroxyamphetamine. There is a second stereoisomer, the threo- isomer, but it has no trivial name. So it is called pseudoephedrine, or the "Sudafed" of sinus decongestant fame.
The pseudo-psychedelics are the 2,4,6-trisubstituted counterparts of the 2,4,5-trisubstituted psychedelics. Almost all of the 2,5-dimethoxy-4-something-or-other compounds are active and interesting whether they be phenethylamines or amphetamines, and it is an exciting fact that the 2,6-dimethoxy-4-something-or-other compounds are going be just as active and just as interesting. A number of examples have already been mentioned. TMA-2 is 2,4,5-trimethoxyamphetamine (a 2,5-dimethoxy-substituted compound with a methoxyl at the 4-position). The pseudo- analogue is TMA-6 (2,4,6-trimethoxyamphetamine) and it is every bit as potent and fascinating. Z-7 could be called pseudo-DOM, and although it is quite a bit down in potency, it is an active drug and will both demand and receive much more clinical study some day.
Will the other 2,4,5-things spawn 2,4,6-things that are active? Without a shadow of a doubt. Chemically, they are much more difficult to synthesize. The 2,5-dimethoxy orientation made the 4-position a natural and easy target. The 2,6-dimethoxy orientation pushes for 3-substitution, and the 4-position is completely unnatural. Tricks are needed, but tricks have now been found. The above synthesis of pseudo-2C-T-4 shows one such trick. This is, in my opinion, the exciting chemistry and psychopharmacology of the next decade. Well over half of all the psychedelic drugs mentioned in Book II are 2,4,5-trisubstituted compounds, and every one of them has a (potentially active) 2,4,6-pseudo-counterpart.
It goes yet further. The antidepressant series of "Ariadne" compounds are 1-phenyl-2-aminobutanes. But the 1-phenyl is again a 2,4,5-trisubstituted compound. The 2,4,6-isomer will give rise to a pseudo-Ariadne family, and I will bet that they too will be antidepressants. The 1-phenyl-2-aminobutane analog of psi-2C-T-4 is the 2,4,6-analogue and it has been prepared as far as the nitrostyrene. It has not yet been reduced, so it is not yet been evaluated, but it could be a most remarkable psycho-pharmacological probe.
And it goes yet yet further. Think back to the six possible TMA's. TMA and TMA-3 were relatively inactive. And TMA-2 and TMA-6 were the interesting ones. The first gave rise to the last twenty years of psychedelic chemistry, and the other (as speculated upon above) will give rise to the forthcoming ten years. But what of TMA-4 and TMA-5? Both showed activity that was more than TMA but less than that of the -2 or -6 isomers. Could they, some day, provoke yet other families of psychedelics? Maybe the 3-position of these two might be focal points of leverage as to psychological activity. What are the letters that follow y in the Greek alphabet? If I remember correctly, the next letter is the last letter, omega. So, I guess that Nature is trying to tell us something, that the -4 and -5 isomers will not engender interesting families. What a pity. The chemistry is so unthinkably difficult that it would have been a true challenge. My next incarnation, maybe?
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