Dear there is no need to use so expensive base because just for the reaction between alcohol and n-butyl chloride it is simple SN2 reaction Deprotonation will be done when alcohol attack through its lone pair on alkyl halide as aresult oxonium fprmation will takes place then weak base can easily remove the atach proton to the oxygen so use potassium carbonate or pyridine as a base

Dear there is no need to use so expensive base because just for the reaction between alcohol and n-butyl chloride it is simple SN2 reaction Deprotonation will be done when alcohol attack through its lone pair on alkyl halide as aresult oxonium fprmation will takes place then weak base can easily remove the atach proton to the oxygen so use potassium carbonate or pyridine as a base

Dear Mr. Khan, the main problem is a two-phase reaction mixture (polar alcohol + less-polar n-butyl chloride). I used both sodium carbonate and NaOH, but an efficient reaction was not occurred!? Then, I used emulsifier two make a homogenous one-phase mixture. The yield of reaction was very low!

Did you try, carbonate or hydroxyde as base in an organic solvents like DMF or THF. the base wont desolve, you will have a slury but most reactions do work really well, no need for the biphasic system. Good luck

Dear Bornaghi, I want to use this method in a large scale. Then, using DMF or THF is not economic and makes the reaction very expensive.

Different time, similar reaction: i did use toluene, cheap and easy to recycle.

Hello,

how about n-butyl bromide instead of the chloride? Maybe you can increase yields although it is somewhat more lipophilic. And how about the use of a phase transfer catalyst to improve the reaction...

Regards!

Dear Boyd, How much sodium iodide should I add to mixture?

Dear Drescher, I have used an emulsifier but success is not achieved.

What kind of emulsifier did you use?

SDBS

SDBS (sodium dodecyl benzene sulfonate). With this emulsifier you get a micellar solution, I think. Maybe, the 'unpolar' n-butyl chloride will incorporate within these micelles - and the 'polar' alcohol in its deprotonated form will not get into close contact to the alcohol for desired SN2-reaction.

So I think you need a phase transfer catalyst including a hydrophobic cation (tetrabutylammonium iodide?) that joined the deprotonated alcohol - and this unpolar complex will possibly be transferred into the unpolar phase - and reacts with the n-butyl chloride.

The addition of NaI is also a good idea!

Regards,

Simon.

Is the use of this catalyst economic in large scale reaction? How can I recycle the catalyst? Which base is the better choice, sodium and/or pottasium carbonate or NaOH?

Best Regards,

Masoud

About economics and recycling: it depends a bit on how 'large' is your large scale reaction and what purification method (recrystallisation, chromatography,...) you use. 1-3 mol% of TBAI shoud be sufficient. However, in most cases I did not recover the catalyst.

Regarding the base: I would prefer potassium carbonate. What about stronger bases such as sodium hydride?

Regards,

Simon.

I think that use of NaH is not economic for my work and I must dry the reaction media and it will be so hard in this large scale work.

Ok, but apart from the use of NaH, it is always better - I think - to work under anhydrous conditions.

What kind of alcohol do you use?

Good luck and kind regards,

Simon.

Ethylene Glycol.

So you want to have the mono- or the bis-alkylated product?

For the mono-alkylated product (ethylene glycol butyl ether) - maybe the reaction of n-butanol with ethylene oxide is more useful; or you might purchase it (1L of 99% about 20US$).

For the bis-alkylated product (1-(2-butoxyethoxy)butane) - 18-crown-6 in combination with KOH is often used in the synthesis of this substance. However, the crown ether is not as cheap as TBAI.

Regards,

Simon.

I synthesized mono acetylated product by refluxing EG with equimolar amount of acetic acid. Then I think that I can synthesize the mono butylated product by using equimolar amounts of EG and butyl chloride!? Can I do that?

Well, an acetylation is much easier to handle compared to an alkylation - you only have to remove the water...

For your alkylation - of course - you have to deprotonate the EG; maybe you can also use NaOH; and as solvent t-BuOH. There is one literature: "Improved synthesis of 2-butoxyethanol" by Wang, Xiaochun, Huaxue Shiji (1993), 15, (1), 63. Unfortunately, I have no access to this paper. In the abstract on SciFinder they claim: "Refluxing ethylene glycol with BuBr and NaOH in Me3COH for 2.5 h gave 98.3% BuOCH2CH2OH." Maybe it also works with n-butyl chloride, but the chloride is less active compared to the bromide. Maybe the addition of NaI will help.

Regards,

Simon.

Many thanks for your comments, Simon. I will examine this method.

Very true what Simon has suggested................I would suggest 90-95 % yield of the ether products when alkyl bromides are treated with phenols in present of sodium metal and dimethyl sulphoxide as solvent. Excess heating increases yield in conventional methods. Same can be accomplished with few min exposure of the reaction mixtures in MW at 460-520 W. Molar excess of phenols will always be helpful.

Dear Simon

I reacted EG with 1-butyl chloride in the presence of catalytic amount of KI (5 mol%) and sodium carbonate as base, but the reaction yield was low. I think that using NaOH or KOH will increase the yield but the 1-butanol may be formed. What is your idea?

Kind Regards,

Masoud

Dear Masoud,

I think you might divide the reaction into two steps: at first the deprotonation of the ethylene glycol with NaOH or KOH (I would prefer sodium) in tert. butanol; maybe under reflux - and after that the second step, the reaction with butyl chloride and cat. amount of KI. This two-step-procedure shoul reduce the amount of 1-butanol.

Nevertheless, the use of butyl bromide instead of the chloride is strongly recommended because of its higher reactivity.

Kind regards,

Simon

What about adding NaOH to EG without using solvent, t-BuOH?

The addition of NaOH as solid pellets? Well, I did not try this - but you might get some problems of solubility: if the resulting salt didn't dissolve in the residual EG - and further did not react with the butyl chloride. You use an excess of EG compared to NaOH and also compared to butyl chloride? Otherwise the addition of a solvent might be useful.

But maybe you can try this reaction without solvent in a small entry.

Regards,

Simon.

Ethylene Glycol is the best one

If you are still looking for an answer, then I suggest this simple method:

First , add a suitable piece of sodium to the alcohol & this general reaction occurs:

Na + ROH ---> RO-Na+ + 1/2 H2. RONa is sodium alkoxide which is a strong nucleophile.

Secondly, mix the sodium alkoxide with n-butyl chloride & a fast reaction takes place yielding ether (R-O-CH2CH2CH2CH3) + NaCl. The reaction follows the SN2 mechanism which is a concerted simultaneous one-step.

Wash the salt with water & place in a separatory funnel. I don't know your alcohol but I assume that the lower layer will be the aqueous so this layer is discarded. From the mouth of the sep. funnel, pour the organic layer into a beaker containing a drying agent(e.g. anhydrous MgSO4). Decant the ether & distill it (if high purity is required).

many thanks Nizar, but this method is not economic in industrial scales.