Irregularities in DOB synthesis...

[Bandil]

Swim has now dosed with 5 mg's of the supposed DOB with no real effect. Swim tested the white powder with marquis which simply foamed and did not change colour.

Unfortunately there will be some time till swim has access to HPLC-MS, so untill then i have a puzzle for you bees:

The nitropropene was prepared ala Barium with nitroethane/2,5-DMBA/methylamine which produced canary yellow crystals. The only difference was that 80% formic acid was used instead of GAA to form the methylamine salt.

Next the nitropropene was reduced in THF/LAH. Overnight the condensor clogged and alot of the THF evaporated(50-70% was gone). The residual LAH was neutralised with IPA/water. It took ALOT of IPA/water to neutralize the whole lot. Alot more than with 2CH reductions(per weight of substrate).

The workup was done as usual and produced a substance with amine properties(towards A/B). The yeild seemed reasonable for LAH reductions.

The bromination was allowed to run for 24 hrs and then worked up in the usual manner. Again the yeild seemed fine.

But in the end swim has a product that is negative towards marquis AND 5 mg's bioassay...

Before swim tries again, do any of you have some ideas of what the heck went wrong? It wouldn't seem that the LAH reduction failed as a amine like substance was formed.

Could it be some sort af hydroxyamine(ala MDOH)?

Regards
Bandil

[Barium]

I have made 1-(2,5-dimethoxyphenyl)-2-nitropropene with methylamine, cyclohexylamine, n-Butylamine and ammonium acetate and even though the yields are different the product is the correct one. Perhaps the LAH reduction didn't go to completion. Therefore the need of more water/IPA to quench the LAH. If so, the oxime and N-OH-2,5-DMA are major products.

Edit

I looked this up right after I posted the answer to you.
Varma and Kabalka¹ says that when 1-(2,5-dimethoxyphenyl)-2-nitropropene is made from 2,5-DMBA, nitroethane, GAA and ammonium acetate three diffrent products can be obtained depending on the ratios of the reactants and reaction time. When 2,5-DMBA/EtNO2/GAA ratio of 1:1,5:0,8 is used a 70% yield of 1-(2,5-dimethoxyphenyl)-2-nitropropene was recovered. At a reactant ratio of 1:3:2, the major product was 2,5-dimethoxybenzonitrile (62%), and at a ratio of 1:40::8, with extended reflux time, the major product was 3-(2,5-dimethoxyphenyl)-5-methyl-1,2,4-oxadiazole (24%). Using nitromethane, the only product is the nitrostyrene despite the reaction time and ratios. Perhaps something similar can happen when using methylamine as catalyst?

1. Organic preparations and procedures int. 19 (4-5), 283-328 (1987)

[Bandil]

I think you are right about the LAH reduction. The reactant ratios are quite different in the formation of the different products. It would have to be a 2X miscalculation if it was the the benzonitrile that was formed. Also, that would not have given the canary-yellow crystals. But the nitrile would eat less hydride ions than the nitrostyrene, so it is still an option....

But AFAIK N-OH is sensitive to A/B and the oxime is not. Could a reasonable explanation be that it is the N-OH compound that was formed(perhaps with some pure NH on side). But could the N-OH group cause considerable fissing with marquis? Perhaps some kind of dehydration etetc?

Oh well, it would be boring if chemistry was easy every time anyways, so i'm not complaining

Thanks Barium!

[Osmium]

Well, test your nitropropene (e.g. by TLC) and compare it to a sample made by another reaction. Or compare its melting point to literature values.

Maybe dibromination occured?
If you are courageous enough, take the dosage higher, maybe activity is right around the corner and your material is impure.
If you have access to analytic instrumentation, you surely have access to TLC plates. Check all your intermediates.

[Bandil]

I doubt that dibromination occured. I used 1,1 eq Br2...

But i'm sure i felt "something" at 2,75 mg's(it was a friend that tried 5, and he's unusually sensitive to everything). I'm usually not a sucker for placebo, but the natural "high" of something fresh out of the lab can usually be enough alone

I guess 6 can't hurt me. And yes i will have a bunch of TLC plates, but i just need to get pass these stupid examns before i can return to work(and the alternative work of course    )

But it's still funny that the marquis is totally negative... There should be SOME colourshift unless it was totally screwed.

[Osmium]

> There should be SOME colourshift unless it was totally screwed.

Not necessarily.
Marquis works by making the formaldehyde react with the aromatic ring, and producing coloured bigger molecules whose aromatic rings are connected to each other by -CH2- or -CH2-O-CH2- bridges.
Since DOB already has 4 substituents, and since the two hydrogens left of the ring are next to bulky substituents it's not a given that marquis will react with it, due to steric reasons.

[madprosr]

swim knows the acetonitrile bromination of commerical dma works well   .
the auditory hallucinations are exquisetly other in nature, but it's rough on the system so use liquid measure to dose carefully. swim might sleep at t+ 36h.

imho the masses are even less equipped to deal with BoB DoBBs than with lsd or shrooms though... it doesn't have a wide appeal.

[Prometheuz]

SWIM also had a go at 2,75 mg of the product. It felt quite a lot like a sample aquired on the black market supposed to be DOB, with the same 3-4 hours to kick in, and the same kind of restlessnes. There is definately SOME activity, and I am rather sure it is caused by DOB, though in lower quantities than expected.
The friend who tried 5 mg of the material reacts strange to some compounds.... He thinks 7 mg 5-MeO-aMT is around threshold... So I don't really concider him a reliable source...
This weekend SWIM will test 5,5 mg of the material. SWIM followed the synth as well, and feels rather certain that at least SOME of the material should have ended up right.

[Schwa]

Okay, so this morning the fat man says to the tall guy that he thinks he got a dosed from the vapors when heating the IPA to clean up his DOB.  Dude said he could not even beging to think about driving and things really kicked in around three hours and peaked a few hours later.  What he got was very mild color enhancement and an auditory effect.  The nature of the auditory effect, I did not get, but I did over hear that he did not sleep easily, and that there seemed to be a noticible body load, different, but not much of it.  He made a point over and over though that he could not tell how long it lasted, but he was okay, except for the peaking period.

Interesting to hear the name, bob dobbs, connected to Dob, but then again everything interests me.

What is the acetonitrile bromination...I know...I could look it up, but hey...

[Prometheuz]

Alas, the DOB has proved to be nearly inactive. SWIM ingested 6 mg last night, and the effects were very subtle, and could maybe even be attributed to placebo, though I doubt it.
We think it might be the N-OH version version of the desired compound. SWIM will probably end up trying larger doses later.

[chemotype]

You could always subject it to another reduction if you believe it is the N-OH cmpd.  I'm not sure if that would dehalogenate the bromide, however.

respect...

[yellium]

N-hydroxies are supposed to be just as active as regular phenethylamines / amphetamines. Read it in the PiHKAL entry for FLEA.,  (~ N-hydroxy-MDMA)

[Rhodium]

madprosr: I'd also like to hear about the specifics of that acetonitrile bromination of 2,5-DMA...