08-13-01 23:32
No 204254
again, obit is taking a shot at the impossibility of obit actually getting a new synth. but here goes:
step 1: 1,2,3-trihydroxybenzene + HCCl3 -(OH-)-> 2,3,4-trihydroxybenzaldehyde (a)
obit has no doubt that step works. simple Riemer-Tiemann
step 2: A + DCM -(OH[/sup]-[sup])-> 3,4-MD-2-OH-benzaldehyde (b)(or the 2,3-md-4-oh side product)
not so sure about that step, b/c of the side rxn will drasitcally lower yeilds.
step 3: B+ nitroethane -catalyst-> the hydroxynitropropene.(c)
pretty sure that this will work with decent yeild
step 4: C+ some hydride red. ag. --> the hydroxy-MD-amphetamine
first of all, is it possible. Second, it the product active. third, where would the methylation of the OH go to give best yeilds? after step 3 or 4? after 3 might cause the attack on the Double bond and after 4 might methylate the N. anyways, it's all just an idea- maybe something else useful could come of it. (especially considering, this probably won't work the way obit wishes it would)
(Hive Bee)
08-14-01 16:26
No 204427
How about this tiny modifaction.
Instead of 1,2,3 trihydroxybenzene, use dichlorobenzene and get 2, 4 dichlorobenzaldehyde...
dichlorobenzene is sold as moth balls just about everywhere in the world...
(Chief Bee)
08-14-01 16:43
No 204431
Obit: The reimer-tiemann often gives complex polymers as by-products and has low yields.
The hydroxy-amphetamine is inactive, so you need to methylate it first. I suggest you do all the alkylation steps as your first move.
Jim: The reimer-tiemann formylation only works on aromatic phenols, not deactivated halobenzenes.
(Hive Addict)
08-14-01 20:01
No 204492
are the side rxns like aldol condensation (thinks it's aldol-maybe it's the other one, can't remember the name-alpha hydrogens/no alpha hydrogens?) ? is there a way to minimize this rxn? maybe using a weaker base than OH?
(Chief Bee)
08-15-01 02:14
No 204619
I believe that the side reactions are polymers from the benzene nucleus cross-linking with another benzene nucleus, just like the plastic bakelite frorms from phenol and formaldehyde.
(Hive Bee)
08-17-01 21:13
No 205457
Turning dichlorobenzene into dihydrobenzene would be very easy. Just add heat and NaOH.
Given the relative expense (Cheap as sin) of 1,4-dichlorobenzene, NaOH, acetone, and bleach, I think that this is an alternitive.
(Hive Addict)
08-17-01 23:02
No 205476
how are you going to swap the Cl and OH's ? aromatic halogens don't like to come off that easily.
(Hive Bee)
08-18-01 03:00
No 205531
Phenol is prepared from C6H5Cl and NaOH.
C6H5Cl + NaOH aq. (~15%) @ 300 C --> C6H5ONa
Also there is:
C6H5Cl + H2O (Cu/ silca gel) --> C6H5OH