dormouse
(Member) 04-22-00 22:59 No 108684 |
Halogonation of Safrole: Just the facts! -ReFlux | Bookmark | ||||||
the Hive BB Novel Discourse Halogonation of Safrole: Just the facts! profile | register | preferences | faq | search next newest topic | next oldest topic Author Topic: Halogonation of Safrole: Just the facts! ReFlux Member posted 03-30-99 09:06 PM ---------------------------------------- Well I've become quite interested in persuing the reverend Drone's method for amination (involving bromo-safrole + MeNH2 + PTC), so creating a viable, efficious method for producing bromo-safrole is in order (or Iodo since it is also a good leaving group). So what do we know so far (And please correct me if any of these facts are wrong!) : 1) The method that absolutely does work is anhydrous HBr in Glacial Acetic acid. Problem of course is the HBr gas. It would have to be generated or bought. Has anyone had any success with this method? 2) DMSO + NaBr (Or NaI) + H2SO4. It situ creation of HBr or HI with subsequent halogenation. Has anyone had any success here? 3) PTC Halogenation: Safrole + PTC + HBr (@ Reflux) = Tar. Safrole + PTC + HCl (@ Reflux) = Chlorosafrole (verified by Rhodium). And how about the halide swap, chloro for iodo or bromo? The good reverend has suggested a PTC catalysed swap (ala Finkelstein reaction). Has any one had any success? 4) 48% HBr, 66% HBr & 70% HBr all result in tar? Also, what is the best method for isolation and purification of the halo-safrole from the reaction matrix (particularly, how would it be seperated from unreacted safrole?) Besides the obvious distillation. I think its important that this problem be solved once and for all for all the bees on the hive so lets all get into gear and solve it! -ReFlux 3. I dreamed a cold PTC bromination with 48% HBR and OTC PTC. The dream was never completed. See the thread "The Tradgedy of Incomplete Experiments - PTC Bromination " in this forum. 4. Polish dudes had success with 70% at 0C. See ref on Rhodium's page. There is little data on bromosaf besides its bp under strong vac. so distillation is still the method of choice. Contact Us | the Hive Powered by: Ultimate Bulletin Board, Version 5.39a |
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