01-09-04 03:14
No 481322
Swim was bored while waiting for ether, so decided to take a stab at Toennie's method for pseudonitrosites.
20ml Asarone (crudely distilled from indian calamus oil; still yellow tint) was dissolved in 170ml GAA. A solution of 15g NaNO2 in 40-50ml dH2O was made and added dropwise at a rate between 1 drop/10sec to 1 drop/20 sec. Addition was complete at T+5h. The reaction vessel was lightly cooled in an ice bath, and the solution was stirred on a low setting (no vortex).
Initially, each drop formed greenish swirls (monomer) which dissolved (and forming dimer), eventually turning the virtually clear solution into a light yellow. Looks good so far.
Small bubbles can be seen being evolved. At about the halfway point, the solution turns orangish. Uh oh.
At T+4h, the solution is a deep, dark red. After the addition is complete, the solution is a purplish red.
The contents of the reaction vessel are poured into a 500ml beaker.
Swim has hope though that this purplish solution can be saved! In hopes of driving out the nitrosites, ~200ml dH2O was added and at each drop of water, the good color, yellow, swirls formed in solution but were immediately dissolved in the purple. But, when all the water had been added, a gradiated (is that a word?) layer formed. A small, dark purple layer is on the very bottom and the color gets progressively lighter upwards, the middle being orangish and getting lighter still until there is a thin yellow layer on top. There seems to be no precipitate yet.
Any ideas on what is happening here? And on swim's next actions?
(Hive Bee)
01-09-04 04:46
No 481337
after ~3 hours the gradient is gone and the solution is now a solid orangish brown color. Still no sign of precipitate, but the solution is very cloudy. It is also still bubbling. What are these bubbles? puzzling...
(LinguisticBee)
01-09-04 04:57
No 481340
have you read this? Post 36661 (Antibody2: "pseudonitrosites via Toennies method", Novel Discourse)
much later after we finally got the asarone rxn to work (using good Et2O) i realized that that purple shit from the GAA rxn was polymerized asarone. Sad but true.
my advise to you is get some ether, it is easily available OTC as cold weather engine start (or whatever brand they sell near you) In truck garages they sell it in 1l canisters
. but unfortunately asarone is the most difficult of all propenylbenzenes to run this rxn on so if from an OTC source your ether must be distilled 1st.If you are hell bent on the GAA method, at least get it to work on isosafrole or anethole first, to work out the rxn details before attempting it again on such a acid-senstive precurser.
afterthought - oddly eneough Chromic reported a decent yeild of asarone glycol from a peracetic oxidation (didn't survive the hydrolysis step tho) so it is possible that it isn't asarone acid sensitivity causing the trouble here maybe it being in contact with NaNO2 as well is part of the problem, but i am speculating now
We are all just witnesses.
(Hive Bee)
01-09-04 05:59
No 481355
Yes, read everything possible on pseudonitrosites. Swim will use ether once it is "ready", but in the meantime swim thought why not try at least one experiment with GAA, which is plentiful. Calamus oil is pretty cheap and inconspicuous too.
Is the acid sensitivity applicable here? On Rhodium's page, why asarone cannot undergo peracid treatment...it says that the epoxide intermediate is acid sensitive and is the cause of failure. But there is no epoxide being formed here? and the bubbling is pretty mysterious since it is definetely not any NOx gases. Anyway, swim will be "playing" with this solution tomorrow morning =P
(Hive Bee)
01-09-04 21:32
No 481455
Ok swim finally gives up trying to workup the solution. Nothing useful was uncovered except red goo that dissolved in alcohol. What could have been happening? The green was observed, so the monomer was formed, and then the solution turned yellow. But this is strange because the yellow dimer should be insoluble, but the yellow remained in solution. Perhaps it's slightly soluble in the GAA? And why would yellow swirls be formed when water was added to the end solution? the cloudy yellow swirls would eventually be swallowed up by the dark solution. anyway, this experiment is done now.
(LinguisticBee)
01-10-04 00:21
No 481489
But this is strange because the yellow dimer should be insoluble, but the yellow remained in solution. virtually every pseudonitrosite rxn Ab2 has seen the ether was yellow after the pseudonitrosites was filtered off (unless it progresed to ugly red!), and stayed that way, perhaps it is NO2 in solution. I only say this beacause Ab2 always recyles his ether and at the end of each recovery distillation there was a red cloud of NO2 that came over(it turns red on contact with O2) so it was obviously some NO2 disolved in the ether. maybe it is the same with GAA.
We are all just witnesses.