Sciencemadness Discussion Board

Dihydrocodeine O-demethylation?

jon - 31-12-2006 at 23:33

yes, there was a discussion on this at synthetikal.org just before they went offline it gave a reference for this being done in hydrobromic acid dissolved in acetic acid the HBr was 10%.
I had a reference in Chem. Ber. but it was too old the library did'nt have it.
hydrocodone is demethylated by 48% (aq) hydrobromic acid in 95% yeilds. I guess they use 10% HBr in this case is the 6-OH group likes to react SN2, maybe I'm wrong.

Biginelli - 1-1-2007 at 04:36

SN2 in such polar conditions?

jon - 2-1-2007 at 10:56

maybe dehydration which is an E-1 or E-2 reaction followed by (markovnikov) addition, i dunno i just know that's the conditions i read on specifically dihydrocodiene. yet for hydrocodone the acid used is aqueous HBr. so the 6 keto, and the 6- hydroxy react differently to acids.