aliced25 - 15-5-2013 at 16:40
Ok, I'm considering trying to find a route to p-methoxyphenylacetic acid and out of two options, anethole seems like the best bet (given the variable
nature of estragole/methyl chavicol content in Basil oil).
So either Mn(III) Acetate or bromine/KOH to the diol, then H2SO4 to the list 1 Ketone. Has anyone got any literature examples of a haloform reaction
working with this "type" of ketone? Problem is, the few references I have seen suggest that this specific type of ketone is overly reactive, with most
normal methods leading to the benzaldehyde/anise aldehyde or benzoic/anisic acid which I'd prefer to avoid.
I know the haloform is the normal test for methyl ketones, I'm just making sure.
killer_lapin - 15-5-2013 at 18:55
p-methoxyphenyl acetic acid as two carbon alpha to the carbonyl, these two carbone can be deprotonated to form an enolate. In the haloform reaction
the base is weak so the enolate is in equilibrium with the ketone, because of the phenyl group the enol form when deprotonating the carbon next to the
phenyl group is stable so the reaction will proced this way. to sum up you won't form p-MeOphenylacetic acid but probably
3,3-dichloro-3-(p-MeOphenyl)acetone or a mixture of chlorinated product.
zed - 17-5-2013 at 12:29
Anise, which grows wild in my home town (SF) is just loaded with anethole.
The common route to diols and thus to methyl ketones of this type, is via treatment with 30% peroxide/with formic acid, in acetone.
The phenylisopropylamine derived from this ketone is known to be fairly toxic. But, the ketone is not a list one material in this jurisdiction.
Direct oxidation of Anethol to p-methoxy benzoic acid may be possible.
Thereafter, dry distillation with Calcium Salts of Acetic Acid, would probably yield the acetophenone.
Which could be rearranged to the phenyl-acetic acid, via the Willgerodt reaction.
[Edited on 17-5-2013 by zed]
[Edited on 17-5-2013 by zed]