Re: Synthesis of 3,5 dimethoxy benzyl alcohol

On Mar 28, 5:10 pm, "Ron Jones" <r...@xxxxxxxxxxxxxxx> wrote:
Yabahoobs wrote:
On Mar 28, 2:46 pm, "Ron Jones" <r...@xxxxxxxxxxxxxxx> wrote:
Yabahoobs wrote:
On Mar 26, 5:22 pm, Anonymous Sender
<anonym...@xxxxxxxxxxxxxxxxxxxxx> wrote:
I've been asked to develop a means of synthesis of 3,5
dimethoxy benzyl alcohol. The meta-addition of the second
-OCH3 group is giving me trouble.

What is / are the common means of synthesis for this
compound ?

What is this? A homework problem? Synthesize FROM WHAT?
"From benzene, any organic reagent of two carbons or less,
and any inorganic reagent, design syntheses of the following
compounds ..."

If 3,5-(MeO)2-Ph-CH2OH was needed for a 'real lab', you
know that you'd just buy it; it's not expensive. If, for
some reason, you didn't want to buy it, there is another
even cheaper starting material (75 cents/gram from Aldrich)
that is only one (decent) step removed from the target.

But maybe you want an isotopic label in there. You could
design a complex synthesis for labeling every position.

When is the homework due?

The goal is to find 3 ways to get to the target from catechol or
phenol.

Here's one to get you rolling then...
1. Phenol to Bromobenzene (PBr5)
2. Bromobenzene to Benzoic Acid (Grignard + CO2)
3. Benzoic Acid to 3,5-Dihydroxybenzoic Acid (fuming H2SO4 - Org
Synth)
4. 3,5-Dihydroxybenzoic Acid to 3,5-Dimethoxybenzoic Acid (Dimethyl
sulphate)
5. 3,5-Dimethoxybenzoic Acid to 3,5-Dimethoxybenyl Alcohol (LiAlH4
in THF
or BH3 in THF)

--
Ron Jones
Process Safety & Development Specialist
Don't repeat history, unreported chemical lab/plant near misses
athttp://www.crhf.org.ukOnlytwo things are certain: The universe
and human stupidity; and I'm not certain about the universe. ~
Albert
Einstein

How bout if we only have benzene available ? By the way I greatly
appreciate your help with this.

Benzene! Benzene is a PITA. It's fairly unreactive, not to mention
carcinogenic (that's because even the body's enzymes can't chew it up, so it
accumulates, and is only excreted *very* slowly).
But if you must... Convert it to Bromobenzene with bromine + catlayst (Fe,
Zeolite) or use N-Bromosuccinimide + Trifluoroacetic.

--
Ron Jones
Process Safety & Development Specialist
Don't repeat history, unreported chemical lab/plant near misses athttp://www.crhf.org.ukOnly two things are certain: The universe and
human stupidity; and I'm not certain about the universe. ~ Albert
Einstein

LoL...Certainly not the ideal way...This is just an academic excursion
Ron. Thanks for the help.
.

Relevant Pages

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