[dumbblondegirl]

Does the process of halogenating methyl alcohol work for all alcohols?

Will mixing an alcohol with KI/NaI or KBr/NaBr or NaCl/KCl halogenate the alcohol and yield NaOH/KOH or does an acid have to present?

Also I'm trying to figure out a way to reduce benzoic acid to toluene. I realize one can use NaOH to reduce it to Benzene, or LiAlH to reduce benzyl alcohol. I wanted to know if I were to dissolve the Benzoic Acid in solvent then add NaOH solution + Al if it would reduce to Toluene? Or what the product would be.

Thanks in advance

[lancenti]

If the process you refer to is the use of PCl₅/PBr₅/SOCl₂, then I believe that it works for all alcohols. Not too sure if there are any exceptions, though.

Using HX would be required, since OH^- is a bad leaving group.

[uvcyclotron]

AFAIK the reaction of ROH with either PCl₅ or PCl₃ or red P/Cl₂ or SOCl₂ or HX, all of them result in cleavage of the C---OH bond.

And for the conversion to toluene you can reduce to benzyl alcohol using LiAlH₄, and then try heating the mixture under acidic conditions followed by hydrolysis, to get Ph-CH₃ i.e toluene..

[SVXX]

Carboxylic acids can be straightaway reduced to alkanes using hydrogen iodide in conjunction with red phosphorus. It is a mighty strong reducing agent. So to reduce benzoic acid to toluene, use HI/Red P.
Another method, although not so much well known, is to use the Arndt Eistert synthesis to increase the carbon chain of benzoic acid by a -CH₂ group. This would make it benzyl carboxylic acid, Ph-CH₂-COOH. Now you can perform a decarboxylation using NaOH/CaO to get toluene.

[uvcyclotron]

Carboxylic acids can be straightaway reduced to alkanes using hydrogen iodide in conjunction with red phosphorus. It is a mighty strong reducing agent. So to reduce benzoic acid to toluene, use HI/Red P.

Mighty strong reducing agent it is, still it sadly can't reduce carboxylic acids to alkane easily, as this reaction leads to very poor yield of R-CH₃ from R-COOH As Far As I Know (AFAIK !) This is so because the nascent H formed in this reaction forms H₂ and gets exhausted since the intermediate formed from the substrate is unstable ( R-C(OH)₂-H).

On the other hand, the method using Arndt-Eistert synthesis seems great to me, I am just thinking why that didn't occur to me! 
The only problem it has though is that the whole synthesis is a 4-step process (with the nitrene intermediate involved, followed later by Wolff Rearrangement), which would be longer and hence rather use the LAH followed by hydrolysis method..

[OC pro]

Another method, although not so much well known, is to use the Arndt Eistert synthesis to increase the carbon chain of benzoic acid by a -CH₂ group.

Any good educated organic chemist with at least M. Sc. level knows this reaction very well. It´s a classic one.

Another way to convert benzoic acid into toluene: reduction to benzyl alcohol, conversion to mesylate, reduction of the mesylate with lithium aluminum hydride.

[SVXX]

Ah OC pro I meant no insult to regular or professional chemists, I was talking about us students!
uv, I have no idea whether it leads to poor yield of products. If that's so, let's forget about that method.
And here's another method which is so simple it struck none of us : decarboxylate benzoic acid straightaway and then perform a Friedel-Crafts alkylation with methyl chloride in AlCl₃!

[g-bones]

Could reduce to the alcohol, halogenate and reduce under radical conditions (Bu3SnH and AIBN).  just another suggestion 

[OC pro]

Methylation of aromatics with MeX gives always bad yields for the mono-methylated compounds. In literature, this has no precedence at all means no one is doing like that.

@g-bone: I had the same in mind. Would work quite good. I had always very good results with Barton-McCombie reaction. A good trick. Recrystallization of the commercial AIBN from MeOH. Gives fine needles of AIBN being highly reactive.

[SVXX]

Methylation of aromatics with MeX gives always bad yields for the mono-methylated compounds. In literature, this has no precedence at all means no one is doing like that.

So much for simplicity....