06-18-03 07:33
No 440821
In this synth
../rhodium /methyle
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11.0 grams (0.1 mol) catechol is dissolved in 1000ml of 20% NaOH, and 3.2 grams (0.1 mol) of cetyltrimethylammonium bromide is added. The mixture is heated to 60°C for 30 minutes and then allowed to cool to room temperature, whereupon 21.2 grams (0.25 mol) of dichloromethane is added with stirring. The mixture is then heated to 80°C with a good reflux condenser for 5 hours, the solution saturated with NaCl and filtered. The solution is then extracted with 3x50 ml CH2Cl2, the pooled extracts washed with 50ml 20% NaOH to remove any phenolic materials, and then with 50 ml brine. The solution is dried over MgSO4, and the solvent removed under vacuum. Yield 90% of 1,3-benzodioxole.
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Could the Phenylacetone be methyleneated in this this manner without anything reacting with the carbonyl group.
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(Active Asperger Archivist)
06-18-03 12:29
No 440863
Yields would probably suffer a little bit, but you could probably do it.
Act quickly or not at all.
(Moderator)
06-19-03 00:41
No 440973
Ketones in the presence of base would polymerize due to an aldol condensation. Protecting the ketone as an acetal might help.
(Active Asperger Archivist)
06-19-03 11:37
No 441090
on a small scale with and without protection to see which gives better overall yields. If the NaOH is only 20% then I don't think that condensation will predominate. It will happen, but is it to such a degree as to warrant the use of a protecting agent (adding and removing slightly lowers yields- unless we have a patent that shows quantitative addition and removal).
Act quickly or not at all.
(Hive Addict)
06-19-03 14:14
No 441126
would the phlactamide be suitable to make the rxn work??
VL_
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(Active Asperger Archivist)
06-19-03 18:45
No 441178
With low temperatures and quick reaction times you should be ok, but I think the amide might hydrolyze (basic conditions)
Act quickly or not at all.