Pihkal
Page 96
The above crude 3,4-dimethoxyphenol was dissolved in 200 mL EtOH, and treated with a solution of 38.1 g KOH in 300 mL hot EtOH. The clear solution of the potassium salt was a deep red color, and was promptly treated with 94.3 g allyl bromide, at a rate commensurate with the exothermic reaction. The mixture was held at reflux for 2 h. This was then added to 1 L H2O and extracted with 5x100 mL Et2O. The extracts were pooled, and removal of the solvent under vacuum gave a residue of 98 g of a black oil. This was distilled at 104-108 !C at 0.7-1.0 mm/Hg to give 59.3 g 1-allyloxy-3,4-dimethoxybenzene as a pale yellow oil with a greenish cast.
A total of 59 g of the neat 1-allyloxy-3,4-dimethoxybenzene was provided with an internal thermometer, and heated with an open flame.
The color quickly became purple, then lightened to a red at 70 !C, and finally to a pale pink by 210 !C. At 240 !C an exothermic reaction set in with the temperature going up to almost 290 !C. It was held in the 270-280 !C range for several min, then allowed to return to room temperature. GC analysis showed two peaks, the second and major one being the desired 1,2,4,5-isomer. A small sample was caught by prep-GC, and it successfully seeded the crude Claissen rearrangement product. The isolated 2-allyl-4,5-dimethoxyphenol, pressed on a porous plate, had a mp of 39.5-40.5 !C which was improved to 41.5-42
!C by recrystallization from hexane.
To a solution of 9.7 g 2-allyl-4,5-dimethoxyphenol in a few mL EtOH, there was added a solution of 2.8 g KOH in 25 mL boiling EtOH followed by 5.5 g ethyl bromide. The mixture was held at reflux for 3.5 h and then poured into 200 mL H2O and extracted with 3x100 mL CH2Cl2.
Pooling the extracts and removal of the solvent under vacuum gave a residue of 10.4 g of 4,5-dimethoxy-2-ethoxy-1-allylbenzene as a clear, mobile oil. It was substantially a single component by GC and was used in the following isomerization step without further purification.
A solution of 9.4 g 4,5-dimethoxy-2-ethoxy-1-allylbenzene in 10 mL
EtOH was treated with 20 g flaked KOH, and heated on the steam bath.
The progress of the isomerization was followed by the assay of isolates by GC. After 5 h, the reaction mixture was poured into 250
mL H2O which immediately generated a pasty solid. This was sucked free of solvent and other liquids on a sintered funnel, giving 5.5 g of trans-4,5-dimethoxy-2-ethoxy-1-propenylbenzene as an amber solid with a mp of 65-67 !C. A small analytical sample from hexane had a mp of 68 !C.
A solution of 5.0 g trans-4,5-dimethoxy-2-ethoxy-1-propenylbenzene in 27 g acetone that contained 2.2 g pyridine was magnetically stirred and cooled to 0 !C. There was then added 4.5 g tetranitromethane and, after 2 minutes stirring at this temperature, the reaction mixture was quenched with a solution of 1.5 g KOH in 26 mL H2O. The reaction mixture remained a clear deep orange color, and additional H2O was required to institute crystallization. There was the slow deposition of bright yellow crystals of
1-(4,5-dimethoxy-2-ethoxyphenyl)-2-nitro-propene which weighed, after EtOH washing and air drying to constant weight of 4.4 g. The mp was 75-76 !C.
To a gently refluxing suspension of 3.5 g LAH in 250 mL anhydrous Et2O
under a He atmosphere, there was added 3.9 g 1-(4,5-dimethoxy-2-ethoxyphenyl)-2-nitropropene by allowing the condensing Et2O to drip into a shunted Soxhlet apparatus with the thimble containing the nitrostyrene. This effectively added a warm saturated solution of the nitrostyrene dropwise; the nitrostyrene was very soluble in Et2O. Refluxing was maintained for 2.5 h and the reaction continued to stir at room temperature for an additional 3.5
h. The excess hydride was destroyed by the cautious addition of 225
mL 1.5 N H2SO4. When the aqeous and Et2O layers were finally clear, they were separated, and 75 g of potassium sodium tartrate was dissolved in the aqueous fraction. Aqueous NaOH was then added until the pH was >9, and this was then extracted with 3x100 mL CH2Cl2.
Evaporation of the solvent under vacuum produced 2.8 g of a clear, almost colorless oil that was dissolved in anhydrous Et2O and saturated with anhydrous HCl gas. This initially generated a solid that then oiled out. After a few minutes stirring, this began to solidify again and it finally transformed into a loose fine white solid. This was recrystallized by dissolution in 50 mL warm IPA followed by dilution with 300 mL Et2O. After a few minutes, crystals of 4,5-dimethoxy-2-ethoxyamphetamine hydrochloride (EMM) formed which were removed by filtration, Et2O washed, and air dried. These weighed 2.7 g and had a mp of 171-172 !C. Anal. (C13H22ClNO3) C,H,N.
DOSAGE: greater than 50 mg.
DURATION: unknown.
QUALITATIVE COMMENTS: (with 50 mg) There were no effects.
EXTENSIONS AND COMMENTARY: This was the first of the ethoxy homologues of TMA-2, and it was immediately (well, within a couple of months) run up from an initial dab to 25 milligrams. This was in early 1963, and the lack of activity of EMM was keenly disappointing. This was a level at which the prototype, TMA-2, was very active, and the conclusion was that maybe any change on the molecule would result in a loss of activity. So this approach was shelved for a while, and all efforts were directed into the relocation, rather than the elongation, of the methoxy groups. A few months later, the ethoxy question was addressed again, and the discovery of MEM rekindled full interest in this ethoxy question.
77 ETHYL-J; 2-ETHYLAMINO-1-(3,4-METHYLENEDIOXYPHENYL)BUTANE; N-ETHYL-1-(1,3-BENZODIOXOL-5-YL)-2-BUTANAMINE
SYNTHESIS: A stirred solution of 9.0 g 1-(3,4-methylenedioxyphenyl)-2-butanone (see the recipe for J for its preparation) in 150 mL MeOH was treated with 9.0 g ethylamine hydrochloride, 4.0 g anhydrous NaOAc, and 3.0 g sodium cyanoborohydride. The pH was maintained between 6 and 7 by the periodic addition of HCl. After the base formation had stabilized, there was added an additional 9.0 g ethylamine hydrochloride, 9.0 g NaOAc and 2.0 g sodium cyanoborohydride. With continuous stirring, there was HCl added over the course of 1 h until the final pH was approximately 2. The reaction mixture was poured into 700 mL dilute NaOH, and extracted with 3x75 mL CH2Cl2. These extracts were pooled, and back-extracted with dilute H2SO4. This was washed with 2x50 mL
CH2Cl2, then made basic with dilute NaOH and extracted with 2x75 mL
CH2Cl2. Removal of the solvent under vacuum gave a 0.81 g residue which was dissolved in 10 mL IPA. Neutralization with concntrated HCl formed white crystals spontaneously. These were diluted with Et2O, filtered, Et2O washed and air dried to provide 0.85 g 2-ethylamino-1-(3,4-methylenedioxy-phenyl)butane hydrochloride (ETHYL-J), with mp of 176-177 !C. Anal. (C13H20ClNO2) C,H. The neutral fraction that remained in the organic phase following the dilute sulfuric acid extraction, was recovered by removal of the solvent under vacuum. There was obtained about 5 g of an amber liquid that was largely 2-hydroxy-1-(3,4-methylenedioxyphenyl)butane.
DOSAGE: greater than 90 mg.
DURATION: probably short.
QUALITATIVE COMMENTS: (with 65 mg) Perhaps aware at 20 minutes.
Definitely aware at 45 minutes. Diffusing to nothing at 3-4 hours.
(with 90 mg) I am somewhere between 1 and +. And everything became lost in the evening with a couple of glasses of wine and talk that went on to 3 AM.
EXTENSIONS AND COMMENTARY: And nothing higher has ever been looked at.
If the analogy with the amphetamine counterparts (J with MDA, METHYL-J
with MDMA, and this, with MDE) were to hold up (a drop of about a third in potency with the lengthening of the chain by a carbon atom), one might guess that this compound would be an interesting intoxicant, but probably not until you got up into the area at or above a 200
milligram dose. And that is a lot of chemical for the body to have to handle. Some day, maybe.
78 ETHYL-K; 2-ETHYLAMINO-1-(3,4-METHYLENEDIOXYPHENYL)PENTANE; N-ETHYL-1-(1,3-BENZODIOXOL-5-YL)-2-PENTYLAMINE
SYNTHESIS: A solution of 120 mg mercuric chloride in 160 mL H2O was poured over 4.7 g aluminum foil (Reynolds Wrap, regular weight, cut into 1 inch squares) and allowed to stand until the amalgamation was well underway (about 30 min). The H2O was then drained and the foil
washed with 2x200 mL H2O with thorough draining. There was then added, in sequence and with good swirling and agitation between each addition, 8.5 g ethylamine hydrochloride dissolved in 7 mL H2O, 21 mL
IPA, 17 mL 25% NaOH, 7.1 g 1-(3,4-methylenedioxyphenyl)-2-pentanone (see the recipe for METHYL-K for its preparation), and finally 40 mL
IPA. The reaction mixture was periodically heated on the steam bath to keep the reaction moving and active. After all the metal had been consumed, the mixture was filtered, and the filter cake washed with MeOH. The solvent was removed from the combined filtrate and washings, and the residue suspended in 800 mL dilute HCl. This was washed with 3x100 mL Et2O, made basic with 25% NaOH, and extracted with 3x100 mL CH2Cl2. The pooled extracts were stripped of solvent under vacuum yielding a residue of 6.3 g of an amber oil. This was distilled at 115-125 !C at 0.4 mm/Hg to give 5.61 g of an almost white liquid which was dissolved in 28 mL IPA, neutralized with concentrated HCl, and diluted with 100 mL anhydrous Et2O. The resulting clear solution became cloudy, then set up in a cottage cheese texture, and then all broke up to a beautiful loose solid. This was filtered, Et2O
washed and air dried to give 5.99 g
2-ethylamino-1-(3,4-methylenedioxyphenyl)pentane hydrochloride (ETHYL-K) with a mp of 157-158 !C. Anal. (C14H22ClNO2) C,H.
DOSAGE: (greater than 40 mg).
DURATION: unknown.
QUALITATIVE COMMENTS: (with 40 mg) There was a paresthetic twinge in my shoulder area at about an hour Q other than that, absolutely nothing.
EXTENSIONS AND COMMENTARY: And that is as high a dose as has apparently ever been tried with ETHYL-K. The compounds with the hexane chain (L-series) rather than the pentane chain of the K-series have been made, but they have been spun into the recipe for METHYL-K.
79 F-2; 2-M;
6-(2-AMINOPROPYL)-5-METHOXY-2-METHYL-2,3-DIHYDROBENZOFURAN
SYNTHESIS: To a solution of 43.2 g KOH pellets in 250 boiling EtOH
there was added 96 g 4-methoxyphenol followed by the slow addition of 131.2 g allyl bromide, and the mixture was held under refluxing conditions for 16 h. After cooling, the reaction was added to 1.6 L
H2O, and made strongly basic with 25% NaOH. This was extracted with 3x100 mL CH2Cl2, the extracts pooled, washed once with dilute NaOH and then once with dilute HCl. Removal of the solvent under vacuum gave 93.8 g of 4-allyloxyanisole as a pale amber oil, which was used in the following reaction without further purification.
A round-bottomed flask containing 93 g crude 4-allyloxyanisole was equipped with an immersed thermometer and heated with an external flame until an exothermic reaction set in at 230 !C. The temperature rose to 270 !C and it was maintained there with the flame for five minutes. After cooling to room temperature, the reaction mix was poured into 2 L H2O and made strongly basic with the addition of 25%
NaOH. This dark aqueous phase was washed with 2x200 mL CH2Cl2, and then acidified with HCl. This was then extracted with 2x200 mL
CH2Cl2, and the pooled extracts washed first with saturated NaHCO3 and then with H2O. Removal of the solvent under vacuum gave 65.6 g of 2-allyl-4-methoxyphenol as a clear, amber oil. To a solution of 1.66
g of this crude phenol in 5 mL hexane with just enough CH2Cl2 added to effect a clear solution, there was added 1.3 g phenyl isocyanate followed with three drops of triethylamine. An exothermic reaction ensued which spontaneously deposited white crystals. These was removed and hexane washed to give 2-allyl-4-methoxyphenyl N-phenyl carbamate, with a mp of 88-89 !C. The acetate ester, from the phenol and acetic anhydride in pyridine, did not crystallize.
To a solution of 37.7 g 2-allyl-4-methoxyphenol in 125 mL glacial acetic acid there was added 19 g zinc chloride followed with 63 mL
concentrated HCl. The mixture was held at reflux temperature for 40
min, then cooled to room temperature, diluted with 300 mL H2O, and extracted with 2x200 mL CH2Cl2. The pooled extracts were washed repeatedly with 8% NaOH until the washings remained basic. Removal of the solvent under vacuum gave a clear pale yellow oil that was distilled at the water pump. A fraction boiling at 150-165 !C was 5-methoxy-2-methyl-2,3-dihydrobenzofuran which weighed 25 g and which was a highly refractive colorless oil. The infra-red spectrum indicated that some small amount of hydroxy group was present, but the NMR spectrum was in complete accord with the benzofuran structure. A higher cut in this distillation gave 4.5 g of a phenolic product tentatively assigned the structure of 4-methoxy-2-propenylphenol. The target dihydrobenzo-furan has also been synthesized from the open-ring o-allyl phenol in acetic acid solution with the addition of a catalytic amount of concentrated H2SO4.
To a half-hour pre-incubated mixture of 69 g POCl3 and 60 g N-methylformanilide there was added 29.0 g 5-methoxy-2-methyl-2,3-dihydrobenzofuran and the mixture was heated on the steam bath for 2 h. The reaction mixture was poured into 1 L H2O, and allowed to stir overnight. The brown gummy solids were removed by filtration, and air dried as completely as possible. These weighed 32
g and were shown by GC on OV-17 to consist of two benzaldehyde isomers in a ratio of 7:2. This was triturated under 18 mL MeOH, and the undissolved solids removed by filtration and washed with 6 mL
additional MeOH. The mother liquor and washings were saved. The 17.8
g of dull yellow solids that were obtained were repeatedly extracted with 75 mL portions of boiling hexane (4 extracts were required) and each extract, on cooling, deposited yellow crystals of the major aldehyde. The dried crystals of
6-formyl-5-methoxy-2-methyl-2,3-dihydrobenzofuran were combined (9.5
g) and had a mp of 80-82 !C. The methanol washes saved from above were stripped of solvent, and the sticky, orange solids that remained were enriched in the minor aldehyde isomer (3:2 ratio). Several injections of this crude material into a preparative GC OV-17 column gave sufficient quantities of the RwrongS isomer for NMR
characterization. The 2-methyl group was intact (eliminating the possibility of a dihydrobenzopyran isomer) and the ring meta-proton splitting required that the formyl group be in the benzofuran 7-position. This crystalline solid was, therefore, 7-formyl-5-methoxy-2-methyl-2,3-dihydrobenzofuran.
A solution of 9 g of 6-formyl-5-methoxy-2-methyl-2,3-dihydrobenzofuran in 35 mL glacial acetic acid was treated with 6 mL of nitroethane followed with 3.1 g anhydrous ammonium acetate. This mixture was heated on the steam bath for 4 h, diluted with half its volume with warm H2O, and seeded with a bit of product that had been obtained separately. The slightly turbid solution slowly crystallized as it cooled, and was finally held at 0 !C for several h. The deep orange product was removed by filtration, washed with 50% acetic acid, and air dried to constant weight. There was thus obtained 7.0 g 5-methoxy-2-methyl-6-(2-nitro-1-propenyl)-2,3-dihydrobenzofuran with a mp of 89-90 !C from MeOH.
A suspension of 5.0 g LAH in 500 mL of well stirred anhydrous Et2O at a gentle reflux, was treated with a warm, saturated solution of 7.0 g 5-methoxy-2-methyl-6-(2-nitro-1-propenyl)-2,3-dihydrobenzofuran in Et2O added dropwise. The mixture was kept at reflux temperature for 36 h, allowed to stand 2 days, and then the excess hydride destroyed by the cautious addition of 500 mL 6% H2SO4. The phases were separated, and the aqueous phase washed with 2x200 mL CH2Cl2. A total of 125 g potassium sodium tartrate was added to the aqueous phase, and sufficient 25% NaOH added to bring the pH to about 10. This phase was extracted with 3x150 mL CH2Cl2, and the pooled extracts were stripped of solvent under vacuum. The residual oil (4.8 g, amber in color) was dissolved in 300 mL anhydrous Et2O which, upon saturation with anhydrous HCl gas gave a clear solution that suddenly deposited white crystals. The hydrochloride salt of
6-(2-aminopropyl)-5-methoxy-2-methyl-2,3-dihydrobenzofuran weighed 2.3
g and was not satisfactory as a solid derivative, but it appears that the oxalate salt is both nonhygroscopic and quite stable. It (F-2) had a mp of 216-218 !C and it displayed a textbook NMR.
DOSAGE: greater than 15 mg.
DURATION: unknown.
EXTENSIONS AND COMMENTARY: This m
aterial, which is certainly a mixture of two diastereoisomeric pairs of racemates since there are two chiral centers present, showed no effects at levels of up to 15 milligrams orally. Doses of 100 mg/Kg were without effects in mice following i.p. injections, although half again this amount proved to be lethal.
In rats trained to discriminate LSD from saline, F-2 proved to be about 40 times less potent than the reference compound DOM, requiring some 5 mg/Kg for positive responses. But the human trials were only up to about 0.2 mg/Kg.
This was the prototype compound that was originally put together to justify giving a paper at a marijuana conference in Sweden, in 1968.
Although I had never done much with marijuana or with its principal ingredients, I thought maybe I could bend the topic a bit to embrace some potentially active phenethylamines. There is a story of an international conference held in Geneva a few years earlier to discuss the worrisome decrease in the elephant population. A German zoologist invested a full eight-hour day in a summary of his 21 volume treatise on the anatomy and the physiology of the elephant. A French sociologist presented a lively slide show on the mating rituals and rutting behavior of the elephant. And a rabbi from Tel Aviv entitled his talk: RElephants and the Jewish Problem.S My Swedish talk should have been named RMarijuana and the Psychedelic Amphetamines.S The memorable story of meeting the chief of the Swedish equivalent of the Bureau of Narcotics, and ending up playing Mozart sonatas in the attic of his home, has been spun out elsewhere in the book.
The original concept was a grand plan to imitate two of the three rings of tetrahydrocannabinol. There is an aromatic ring (with an alkyl group and two oxygens on it) and it is fused to a pyran ring with a couple of methyl groups on it. So, if one were to tie the methyl group at the 4-position of DOM around with a short carbon chain into the oxygen atom at the five position, one could squint and say that the resulting amphetamine was kinda something like an analogue of THC. Thus, the resulting six-membered ring (a pyran) or five-membered ring (a furan) could be peppered with methyl groups at different locations (and up to two per location). If the ring was a five-membered structure, then the parent system would be a benzofuran, and the location of methyl groups on the ring would be indicated by the appropriate numbers following the letter RFS which would stand for RfuranS. And if it were to be a six-membered ring, the resulting benzopyran would be indicated with a RPS for pyran, and again the methyl group or groups would be indicated by the substitution position. This code would cover all polymethylated homologues with codes that would look like F-22 and P-2234. If any of them showed up with fascinating activities, I would extend methyls to ethyls, and work out some whole new naming code at some future time. An early system, naming this compound 2-M for a methyl group on the 2-position of the furan ring, was abandoned when it became apparent that the pyran world would screw everything up.