• N&PD Moderators: Skorpio | someguyontheinternet

Acid, dragonflies and the 5HT2A receptor

Er, yes - I got it horribly wrong with that one. It wasn't until I discovered that the carboxyl group (part of the amide function) formed hydrogen bonds with the serine amino acid residue that I started to have doubts about that one. It's just that it's the serine residue that forms hydrogen bonds to the 5-OH/OCH3 of simple tryptamines; with LSD it's possibly that the methoxy group causes steric hinderance problems
 
Dynamic image showing structural relationship between ergolines, tryptamines & phenethylamines - see att. animated GIF

Hey, I've just learned how to make complex animated GIFs, so I thought I'd 'show-off'!
 

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  • LSD-DMT-DOM (450x450).gif
    LSD-DMT-DOM (450x450).gif
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Ok i'll give u that but LSD and DOM share practically nothing in common. Any structural overlay is just a coincidence.
 
I am not very familiar with such stuff, but it looks nice!!
A question:
Couldn’t it be possible that the 2C-X series are rather comparable to the 5-MeO-tryptamine derivatives, whereas the 4-oxygenated psilocin derivatives have rather similarities to the 2,4,6-orientated pseudo compounds? This is just what sprang into my mind, and it might be nonsense, when you have a closer look to the distance of the alkyl chain nitrogen to the highlighted lone pair donors.
This would also imply that a halogen or a methyl group at the indolic 6 position (the X) would increase the affinity of tryptamines.
 
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EN21 said:
I am not very familiar with such stuff, but it looks nice!!
A question:
Couldn’t it be possible that the 2C-X series are rather comparable to the 5-MeO-tryptamine derivatives, whereas the 4-oxygenated psilocin derivatives have rather similarities to the 2,4,6-orientated pseudo compounds? This is just what sprang into my mind, and it might be nonsense, when you have a closer look to the distance of the alkyl chain nitrogen to the highlighted lone pair donors.
This would also imply that a halogen or a methyl group at the indolic 6 position (the X) would increase the affinity of tryptamines.


You drew the 2Cs 'upside down', at least if you want to compare the PEAs to the indoles. Flip them upside down and you will see that the oxygen from the 5-MeO group of 2C-X is in the same position as the indolic nitrogen of LSD and DMT.
 
OOPs!
I should have known this, since all the beautyful explanations from F&B.
Sorry!
It was just one of those stupid ideas.
 
Smyth said:
Ok i'll give u that but LSD and DOM share practically nothing in common. Any structural overlay is just a coincidence.


You're kidding, right? Rats trained to respond to DOM respond to LSD & vice versa. They're both 5HT2a agonists. Did you read any of this thread - I don't think so...

The whole basis of SAR studies is based on structural similarities allowing for similar sort of binding to the receptor - are you going to say all SAR studies are coincidence?

EN21: I'd never notoced that about the psi-series of phenethylamines - they'd put a lone pair in the same place psilocin does (eq of the 9,10-double bond of LSD - all present a concn of negetive charge/electrons) - would explain their potency
 
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I did read this thread but after looking at your pictorial it showed me just how disimilar DOX is from LSD. There seems to be some crossover between 5-MeO-tryptamines and the 2,5-DiMeO compounds though.
 
^Not really. They're both 5HT2a agonists and they both bind to the same parts of the transmembrane protein that forms the receptor.

The oxygen (well the lone paie electrons of said atom) of the 5-methoxy forms a hydrogen bond to the same amino acid residue as the indolic nitrogen's lone pair and the lone pair of the 2-methoxy group forms a hydrogen bond to the same a.a. residue (I remember this one - serine in this case) as the oxygen of a 5-methoxy indole or the oxygen of the carbonyl group that is part of the diethylamide structure.

They may feel subjectively different, but so do all of the psychedelic hallucinogens, yet they all share a few very important characteristics that make them psychedelics and without which they'd be just plain stimulants/alpha adrenergic agonists
 
As it was brought up in another thread, I thought I'd ask if anybody has any references to 4-amino-N,N-dialkyltryptamines and their 5HT2a affinity. Thet should (in theory) have similar activity to the 4-hydroxytryptamines as they both have an atom at the 4-position that possesses a lone pair of electrons for binding to the serine amino acid residue of one of the transmembrane helixes of the receptor protein
 
Throwing a meaty bone in here on f&b's suggestion of the beta-methylene substituted psychedelics as a mimick of the LSD double bond.Methinks he's onto something,might give the phenethylamines the "G spot" stimulator on the 5-HT2A receptor.Surely such compounds can be made.Though it looks we might get some MAO activity,but that hasn't been a negative.Below are the closest structures known,I fear the structures won't come through:




Stabase-protected 2-chloroallylamine: a useful synthon for primary allylic amines via nickel-catalyzed cross-coupling. Bargar, Thomas M.; McCowan, Jefferson R.; McCarthy, James R.; Wagner, Eugene R. Indianapolis Cent., Merrell Dow Res. Inst., Indianapolis, IN, USA. Journal of Organic Chemistry (1987), 52(4), 678-81. CODEN: JOCEAH ISSN: 0022-3263. Journal written in English. CAN 106:102001 AN 1987:102001 CAPLUS

Abstract

Grignard reagents couple effectively with the stabase protected form I of 2-chloroallylamine in the presence of 0.005-0.01 mol equiv. of [Ph2P(CH2)3PPh2]NiCl2 to provide an improved synthesis of 2-substituted allylamines. For example, 2-thienylmagnesium bromide was converted to thiopheneethanamine II in a one flask procedure in 78% yield. II is useful as an inhibitor of dopamine b-hydroxylase.



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Unsaturated heterocyclic amines as potent time-dependent inhibitors of dopamine b -hydroxylase. Bargar, Thomas M.; Broersma, Robert J.; Creemer, Lawrence C.; McCarthy, James R.; Hornsperger, Jean Marie; Palfreyman, Michael G.; Wagner, Joseph; Jung, Michel J. Indianapolis Cent., Merrell Dow Res. Inst., Indianapolis, IN, USA. Journal of Medicinal Chemistry (1986), 29(3), 315-17. CODEN: JMCMAR ISSN: 0022-2623. Journal written in English. CAN 104:129726 AN 1986:129726 CAPLUS

Abstract

RC(:CH2)CHR1NHR2 (I, R = 2-thienyl, 3-thienyl, 2-furyl, 3-furyl, Ph; R1, R2 = H, Me) were prepd. and tested for dopamine b-hydroxylase inhibition. Thus, RC(:CH2)Me (R = 2-thienyl) was treated with N-chlorosuccinimide to give RC(:CH2)CH2Cl, which was treated with K phthalimide and then N2H2, followed by HCl to give I.HCl (R = 2-thienyl, R1 = R2 = H) (II.HCl). II and also PhC.tplbond.CCH2NH2 were potent, time-dependent inhibitors of dopamine b-hydroxylase, having activities 1000-fold greater than that of I (R = Ph, R1 = R2 = H). PhC.tplbond.CCH2NH2 and I (R ¹ Ph, R1, R2 = H, Me) also showed antihypertensive activity in rats.



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Enzyme-activated irreversible inhibitors of monoamine oxidase: phenylallylamine structure-activity relationships. McDonald, Ian A.; Lacoste, Jean Michel; Bey, Philippe; Palfreyman, Michael G.; Zreika, Monique. Strasbourg Cent., Merrell Dow Res. Inst., Strasbourg, Fr. Journal of Medicinal Chemistry (1985), 28(2), 186-93. CODEN: JMCMAR ISSN: 0022-2623. Journal written in English. CAN 102:58260 AN 1985:58260 CAPLUS

Abstract

The title compds. I (R and R1 = H, Br, Cl or F; R2 = H or OMe; R3 = H, OH, OMe or CF3; R4 = H, Cl, OH, Me, or OMe) were prepd. as HCl salts by several routes and evaluated in vitro by incubation with a crude rat brain mitochondrial monoamine oxidase (MAO) prepn., and in vivo in mice. With the exception of (Z)-3-chloro-2-phenylallylamine, which acted as a competitive inhibitor, all I caused a time-dependent inhibition of MAO when selective substrates were used. (E)-3-Fluoro-2-(4-methoxyphenyl)- and 2-(3,4-dimethoxyphenyl)-3-fluoroallylamine were as selective for the B form of MAO as deprenyl. (E)-3-Fluoro-2-phenylallylamine given to mice at 1 mg/kg, i.p., gave good inhibition of MAO in the brain and heart which lasted £48 h. Structure-activity relations were discussed.





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Characterization of a Series of 3-Amino-2-phenylpropene Derivatives as Novel Bovine Chromaffin Vesicular Monoamine Transporter Inhibitors. Perera, Rohan P.; Wimalasena, D. Shyamali; Wimalasena, Kandatege. Department of Chemistry, Wichita State University, Wichita, KS, USA. Journal of Medicinal Chemistry (2003), 46(13), 2599-2605. Publisher: American Chemical Society, CODEN: JMCMAR ISSN: 0022-2623. Journal written in English. CAN 139:100849 AN 2003:347315 CAPLUS

Abstract

A series of 3-amino-2-phenylpropene (APP) derivs., e.g. I (R1 = H, F, Cl, HO, Me, MeO, etc.; R2 = H, HO, MeO; R3 = R4 = H, Et; R3 = Me, R4 = H), was synthesized and characterized as novel competitive inhibitors, with Ki values in the mM range, for the bovine chromaffin granule membrane monoamine transporter(s) (bVMAT). Although these inhibitors are structurally similar to the bVMAT substrate tyramine, none of them were measurably transported into the granule. Structure-activity studies have revealed that, while the 3- or 4-OH groups on the arom. ring enhance the inhibition potency, Me or OMe groups in these positions reduce the inhibition potency. Halogen substitution on the 4-position of the arom. ring causes gradual increase of the inhibition potency parallel to the electron donor ability of the halogen. Substituents on the NH2 as well as on the 3-position of the alkyl chain reduce the inhibition potency. Comparative structure-activity analyses of APP derivs. with tyramine and the neurotoxin 1-methyl-4-phenylpyridinium suggest that the flexibility of the side chain and the relative orientation of the NH2 group may be crit. for the efficient transport of the substrate through the bVMAT. Comparable bVMAT affinities of these inhibitors to that of DA and other pharmacol. active amines suggest that they are suitable for the structure-activity and mechanistic studies of monoamine transporters and may also be useful in modeling the mechanism of action of amphetamine-related derivs.



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Abstract

RR1C:CR2CH2NHR3 (R, R1 = H, F, Cl, Br; R2 = Ph, substituted Ph, naphthyl, indenyl, fluorenyl, heterocyclic; R3 = H, alkyl, CH2P, CH2CH2Ph) were prepd. Thus, treating R4CH2CO2CMe3 [R4 = 3,4-(MeO)2C6H4] ClCO2Et in ClCHF2 gave EtO2CCR4(CHF2)CO2CMe3, which was decarboxylated, dehydrofluorinated, and reduced to give (E)-HOCH2CR4:CHF (I). I was aminated with phthalimide and hydrazinolized to give (E)-II. (E)-II×HCl showed a selectivity for MAO-B inhibition of 500 relative to MAO-A inhibition.









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In the 2Cx/DOx series, the most potent substituents at the 4-position seem to be fluorinated ones (CF3 and SCH2CH2F), and electronegative groups generally seem to give an active compound.

Would adding more fluorines at this position increase the potency? Are compounds like 4-C2F5-2,5-DMA and 4-SF5-2,5-DMA likely to be active or would the larger groups block the binding site? I've only seen the SF5 group in the medicinal chemistry textbook, never come across a compound where someones actually used one...
 
SF5? Do you mean SC2F5? I do not think an SF5 group is possible. I had asked about C2F5 a while ago, and was told it would be very difficult to get the alpha carbon (closest to the benzene ring) to contain fluorine. However the C2H2F3 is quite active.
 
I proposed the SF5 (pentafluorosulfanyl-) derivative on the 2C-TFM thread awhile back.It has been successfully attached to a few benzene derivatives,but its one of those few unexplored holes in chemistry/pharmacology.Fertile ground for explorers.It has all the ingredients to be active on the phenethylamines %) .And its stable as stone.

The pentafluoroethyl of the 2C's is known,posted that in the LSD conference thread.Yeah,it was difficult to synth from what I heard.I guess it will be in the coming Index.
 
He just finished the synthesis at the time,so no trials to report.I'm curious on it as well...
 
Man that will be exciting to try. All of the 'play-ons' of 2C-D and 2C-E (that is some sort of methyl and ethyl at para) excite me. Most of all is 2C-T. Please someone make some 2C-T and send me 2.5g.

I still can't understand why oddballs such as 2C-G, 2C-N, and 2C-T-4 were available at one time, and that potential gem was overlooked.
 
Why do you consider 2C-T-4 an oddball? I find it to be quite a good psychedelic in higher doses, despite quite a body load
 
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