The Hive > Methods Discourse
P2P syntheses of yonder days
Mendeleev:
Wow this is great, I'm really liking the Pd catalyzed alpha arylation and the bromobenzene with propylene oxide to P2Pol and then oxidized to P2P. Several questions though, is 1-Phenyl-2-nitropropene a regulated precursor? I didn't find it in the DEA handbook although all of its precursors like benzaldehyde and nitroethane were regulated. Secondly, I assume the procedure with calcium acetate can be done directly with phenyl acetic acid not its calcium salt, no? Also does anybody else think some of these are a bit impractical except as a possible laboratory curiosity? I saw a couple of procedures where the precursors aren't even commercially available, not regulated, it's just that the lab companies simply don't have them.
armageddon:
Rhodium:
is 1-Phenyl-2-nitropropene a regulated precursor? I didn't find it in the DEA handbook although all of its precursors like benzaldehyde and nitroethane were regulated.
It is not explicitly regulated on a national level as far as I know*, but due to the noxious and unstable nature of nitroalkenes (not to mention a rather low licit demand), they are seldom offered for sale from chem suppliers. But even if the sale of 1-Phenyl-2-nitropropene isn't explicitly prohibited, it sure is a suspicious item and commercial aquisition should be avoided.
Secondly, I assume the procedure with calcium acetate can be done directly with phenyl acetic acid not its calcium salt, no?
That is not a good idea, as the phenylacetic acid may then react with the calcium acetate to form calcium phenylacetate and free acetic acid, which under the temperatures employed will evaporate and escape.
A lowered ratio between the Ca-Phenylacetate/Ca-Acetate leads to an increased formation of undesired dibenzyl ketone at the expense of less phenylacetone. The loss of acetic acid might be compensated for by the addition of more calcium acetate to the mixture, but I fail to see the advantage of using such a workaround compared to preparinging the proper calcium phenylacetate salt beforehand.
Also does anybody else think some of these are a bit impractical except as a possible laboratory curiosity?
Surely a lot of the procedures are obsolete and byzantine, but this compilation is intended to be comprehensive, rather than strictly practical.
* Some US states regulates 1-Phenyl-2-nitropropene though, see http://www.state.co.us/gov_dir/leg_dir/olls/sl1996/sl.295.htm
armageddon:
OK Rhodium I surely would_ve said nothing when you just would've told me to not play the moderator, as I can understand this quite well; but since you tried to convey the impression that I said something wrong, I simply have to reply on that! Here we go...
About "Check your facts":
The "fact" I gave was: "Why do you think a pretty large number of bees use to prepare their own nitrostyrenes!? Better don't try to obtain them through ofiicial sources!"
The "fact" you gave is: "It is not explicitly regulated on a national level as far as I know*, but due to the noxious and unstable nature of nitroalkenes (not to mention a rather low licit demand), they are seldom offered for sale from chem suppliers. But even if the sale of 1-Phenyl-2-nitropropene isn't explicitly prohibited, it sure is a suspicious item and commercial aquisition should be avoided."
Now tell me the difference (besides redundant additional info about the noxious nature of nitropropenes and the low licit demand thing)!
(BTW sorry to interrupt Aurelius' compilation with that;
it doesn't seem to matter anyway)
And about "leave the moderation to the moderators":
WOW! whatta rating! Never seen that before... - but why do you think I would moderate something by stating "I think someone has gone off-topic"?
Greetz A
Rhodium:
Now tell me the difference (besides redundant additional info about the noxious nature of nitropropenes and the low licit demand thing)!
The difference is that you did not answer the question directly - you replied with a question and gave some general advice. What you wrote might imply that 1-phenyl-2-nitropropene actually would be a regulated precursor, which it isn't in most parts of the world, including the EU and in US Federal legislation - just as I wrote in my post above.
My reply also included an example of an exception to this general rule, as well as offering an explanation as to why 1-phenyl-2-nitropropene seldom is found commercially, even though it is not explicitly prohibited to sell.
(BTW sorry to interrupt Aurelius' compilation with that; it doesn't seem to matter anyway)
If you have any further comments, please PM me - this is not the place for a discussion like this. If you are going to publicly argue about every rating you get in any of the forums, I will have to remove your posting privilegies in the chemistry forums, as you are severely cluttering them with posts which constantly are on the verge of being fully insignificant - your two latest posts in this thread does not really add much substance to the topic at all...
[Note to all: These off-topic posts will be removed in due time, as to not clutter this compilation forever...]
WOW! whatta rating! Never seen that before... - but why do you think I would moderate something by stating "I think someone has gone off-topic"?
I believe it is because you want to boost your ego by telling even fresher newbees than yourself about what you feel is appropriate behaviour around here. However, such advice is solely up to moderators and admins to dole out, as those are the only ones who are in a position to decide about appropriate bee-haviour.
If I catch you arguing about ratings or other severely off topic things in the chemistry forums again, prepare to have your posting privilegies suspended for a time. Ratings are off topic to discuss in all the chemistry forums, and should only be discussed in General/Couch/PM, if at all.
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