Post 465461 (https://www.thevespiary.org/talk/index.php?topic=11742.msg46546100#msg46546100)
(Bandil: "Proof of concept!", Novel Discourse) as reference. Swim question would be: is the formic acid really necessary or can it be replace with GAA, which is already owned by the guy?Post 499607 (https://www.thevespiary.org/talk/index.php?topic=9390.msg49960700#msg49960700)
(armageddon: "different routes starting from nitropropenes", Methods Discourse)Post 382254 (https://www.thevespiary.org/talk/index.php?topic=12193.msg38225400#msg38225400)
(Barium: "A great CTH method", Novel Discourse), i've wondered if the IPA (or alcohol used) need to be anhydrous?this document. (https://www.thevespiary.org/rhodium/Rhodium/chemistry/nitrostyrene.reduction.alhg.html)
(https://www.thevespiary.org/rhodium/Rhodium/chemistry/nitrostyrene.reduction.alhg.html)Is that the yield for the reduction of the nitrostyrene or the overall yield starting from the benzaldehyde? If the latter, could you please tell the yields for the two steps?
Ahh, that's only the yield for the reduction. The nitrostyrene was made by treating a solution of 3,4,5-TMBA and nitromethane with methanolic KOH at a low temperature, then treating with acid to accomplish the dehydration. The yield was never calculated, but it SUCKED. It's believed a botched recrystalization attempt actually destroyed some of the material: initially, a nice yellow clumpy solid was obtained from the condensation. This was "dissolved" in boiling isopropyl alcohol. What really seemed to happen was the nitrostyrene oiled out during this process, and formed a separate layer which slowly turned red. This pissed off the chemist royally. Eventually the oil formed a solid which was recrystalized twice more, this time from boiling methanol which worked much better. The final nitrostyrene was around 4.2 grams, from a starting 15 grams of the 3,4,5-TMBA. The final material formed nice platelett-like crystals, but was always a slightly darker color than would be expected. This suggests some remaining impurity, and that the reduction yields might be boostable with more pure material.
Next time, the nitrostyrene will be made with n-butylamine as the catalyst, just because the chemist likes n-butylamine. It was considered sort of ironic that the "easy" part of the synthesis in this case was the reduction and not the condensation..
-SpicyBrown
Post 419399 (https://www.thevespiary.org/talk/index.php?topic=9233.msg41939900#msg41939900)
(Barium: "High-yielding nitrostyrene catalyst", Methods Discourse)Post 523841 (https://www.thevespiary.org/talk/index.php?topic=7684.msg52384100#msg52384100)
(psyloxy: "nBuNH2 in Henry rxn on 25DMB / 345TMB - 1h, 84-88%", Chemistry Discourse)Post 505399 (https://www.thevespiary.org/talk/index.php?topic=10362.msg50539900#msg50539900)
(imp: "Just do it this way!!", Newbee Forum) does work, it's just absolutely imperative that you keep it cold and stirring quite vigorously. If it's not kept cold enough, you'll get a shitty tar and a bad yield of impure material. I had problems keeping it cold enough with a normal water ice bath, if you could rig your stirrer in the freezer however... Hell, just use a dry ice/CH3CN and it'll probably work great.Post 516547 (https://www.thevespiary.org/talk/index.php?topic=10362.msg51654700#msg51654700)
(KidCurry: "Crappy yield", Newbee Forum) from thePost 505324 (https://www.thevespiary.org/talk/index.php?topic=10362.msg50532400#msg50532400)
(KidCurry: "3,4,5-TMBA -> 3,4,5-TMNS", Newbee Forum)KidCurry claims 30-40% yeald with this KOH method (21 gstyrene from 50g aldehyde)https://www.thevespiary.org/rhodium/Rhodium/chemistry/leminger.html (https://www.thevespiary.org/rhodium/Rhodium/chemistry/leminger.html)