11-20-03 16:28
No 472101
Could Etyl acetoacetate react with sodiumethoxide and
5-bromo-1,3-benzodioxole to yield MD-P2P under a standard crossed claisen condensation. Somebody tryed this? And P2P from bromobenzene under the same conditions??? And why not if thats the case, i remember i asked my highscool teacher of this some years ago, and she couldn`t answer me. She said the phenylgroup was to big and there maight be a steric hinder...???
(Chief Bee)
11-21-03 00:07
No 472185
Alkylation of acetoacetate proceeds through an SN2 mechanism, and if you review your organic chemistry literature, you'll discover that aromatic halides does not normally undergo any SN2 reactions at all.
Your only hope here is to either form a benzyne intermediate (utfse/google) which can alkylate the acetoacetate anion or to instead use use acetylacetone as your ketone (../rhodium /p2p.ac
(Newbee)
11-21-03 01:42
No 472212
so it Wouldn`t work with cyanide group instead of Br either? thats to bad..
(Chief Bee)
11-21-03 02:33
No 472222
Cyanide sucks as a leaving group regardless of where it is attached. It will most certainly not abandon a phenyl ring just because an acetoacetate anion happened to sail by...
(Newbee)
11-21-03 17:05
No 472361
Rhodium: aromatic halides does not normally undergo any SN2 reactions at all.
Not even if pushed to really extreme situations? I'm thinking about using ultrasound with external heating..
There is only one thing I can't tolerate and that's intolerance!
(Chief Bee)
11-22-03 12:25
No 472537
No, when a substitution of an aryl halide do occur, it is through another mechanism, such as benzyne formation, Nucleophilic Aromatic Substitution or metal-mediated oxidative addition/reductive elimination processes (usually involving Pd or Cu).
Google on the italicized terms for more information.