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Sterification with HCL
Greetings.
Im aiming to make my own Jazmín alike fragance from benzyl alcohol and acetic acid ussing hcl as catalizer, i have been researching and almost all the proccedures uses sulphuric acid, but i cant use sulphuric acid in my country, because it use or storage is forbiden its called “drug initiator”.
Havr anyone experienced making fisher sterification ussing hcl, does ussing hcl instead of sulphuric makes a Big yield difference?
Thanks you very much
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17 Replies
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I’ve done that reaction but only with sulphuric acid, you will have to try it for yourself.
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It is possible but you have one main problem, water! Esterification only works in anhydrous systems and HCl comes at <35% aqueous solutions. Trying to remove said water by evaporation will evaporate HCl first whilst chemical or adsorption strategies (such as anhydrous Epsom salt or molsieve) will turn HCl into a gas and then you’ve got to run. You may want to try phosphoric acid or acetic anhydride
. In the latter case, you have to gently neutralise the excess acetic acid before solvent extraction or distillation. -
I just can’t imagine the difficulties of using acetic anhydride for anything, if not wearing a complete biohazard suit.
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Pharma said:It is possible but you have one main problem, water! Esterification only works in anhydrous systems and HCl comes at <35% aqueous solutions. Trying to remove said water by evaporation will evaporate HCl first whilst chemical or adsorption strategies (such as anhydrous Epsom salt or molsieve) will turn HCl into a gas and then you’ve got to run. You may want to try phosphoric acid or acetic anhydride . In the latter case, you have to gently neutralise the excess acetic acid before solvent extraction or distillation.
Im thinking in use an aparatus like dean-stark water separator, but it would be awesome that i could use phosphoric acid, have you made an experimento ussing phosphoric?
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Belassi said:I’ve done that reaction but only with sulphuric acid, you will have to try it for yourself.
HI belassi, como estas?. Thanks you very much
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luiscuevasii said:Belassi said:I’ve done that reaction but only with sulphuric acid, you will have to try it for yourself.
HI belassi, como estas?. Thanks you very much
What material is ‘ como estas ‘ ?
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Haha it’s Spanish. We both live in Latin America. I’m good, thanks. I have to close the lab temporarily because we are moving home.
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luiscuevasii said:Im thinking in use an aparatus like dean-stark water separator, but it would be awesome that i could use phosphoric acid, have you made an experimento ussing phosphoric?A Dean Stark won’t really work with aqueous HCl solutions. You’d distil off water and HCl together .No, I have not tried phosphoric acid but theory says it will work nearly as smoothly as sulphuric acid. There are a few reasons why it’s not used, being not reactive enough ain’t one of them.Did you try ordering the final product at Perfumer’s Apprentice? Neglecting the fun part, this might be less hard on time and budget… Glassware is expensive!I don’t see why using acetic anhydride would require a hazmat suit… It has a fairly low reactivity for an acid anhydride and it boils above acetic acid. Slowly dripping it into a chilled solution of benzyl alcohol and neutralisation of eventual residues with a bit of water just before liquid-liquid separation will result in vinegar (or just add bicarbonate solution -> careful, it will bubble like crazy). Also, you can avoid heating as well as strong mineral acids and that’s already a huge advantage over acid catalysed esterification.Besides, esterification with acetic anhydride (making aspirin) is a school experiment you can do with 14-16 year olds .
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@Pharma thanks you for allí the input, sulphuric Acid os forbbiden un my country, It is ussed for making cocaine so is banned, what about ussing hidroflourhydric Acid?, Is strongest and more reactive than phosphoric.
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NO! Sooner or later there will be an accident, it is a horrific chemical.
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Sulfuric acid ain’t banned. It’s just a controlled chemical.
Pretty sure you can just fill the proper paperwork yourself in order to buy it, especially if it’s for smaller amounts.Lots and lots of very small car battery manufacturers and repairsmen buy some of it and they don’t even have a legal department to handle the paperwork, so it’s easy.
What are you trying to synthesize?
Benzyl acetate?
Pretty sure you can buy or import it ready made. Since it’s for fragrance it shouldn’t increase costs too much. -
Hydrofluoric acid? How would you get that? And you’re likely to die faster and terribly painful from handling HF (especially if you try to heat a non-hermetically sealed container) than from getting arrested by police . HF is volatile, super toxic, and gets into your body through your skin and your lungs. Oh, and did I mention that you’re very likely to suffer a lot before or rather until you die? Not joking here! Just as a side note: HF is, at least in water, a rather weak acid, evaporates at room temperature, is safest to handle in HF-pyridine or the like, and dissolves glass. All that makes it very unsuitable as an esterification catalyst.Car batteries (the older ones) contain strong enough sulfuric acid (it’s strongest when they’re charged) for your purpose but you should probably buy fresh battery acid and not use an actual battery since that acid is loaded with lead and hence not very healthy. Though, this didn’t kept me from doing exactly that as a kid
. The pharmacy wouldn’t sell it to a 14 year old but the guy at the garage had no issues with giving me some old batteries (one of which exploded nearly into my face when charging it… always be careful and wear gloves and safety goggles!).As said, I’d try phosphoric acid as a safe alternative. -
@Pharma Hf is legal in My country, can’t Buy fresh battery acid, sulphuric acid is very ilegal arround here, i Will try phosphoric
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When I took over chemistry at my last school I inventoried the storage cupboards and found 2 x 1 litre bottles of HF acid. Now, I am not one to be scared of chemicals, but I called the hazardous disposal people and had someone come around to take it away, and he freaked out when I showed it to him. I have only dealt with one other acid as dangerous, and that was chromic acid. I spilt some chromium trioxide on a vinyl lab floor and it made a hole straight through and cratered the concrete underneath.
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At least, chromic acid does not dissolve glass and it doesn’t kill you (that is, if they find a cure once cancer kickes in). Sorry for the black humour . Chromic acid mixed with sulfuric acid was widely used to clean glass ware until someone found out that chromium VI not only is carcinogenic but also penetrates skin and is somewhat volatile… now we use piranha solution.I’m not saying HF is illegal but here around it’s hard to get and a 50% aqueous solution costs about $1 per 1 ml. The only lab accidents I can remember which happened during my time at the university (the whole uni, not just my lab) and seriously injured people was with HF.
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What do you mean H2SO4 is illegal in your country? There is no way you can outlaw such an important industrial chemical. Buy it with the proper paper work. You won’t need much for fischer esterfication considering it is a catalyst.
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Cafe33 said:What do you mean H2SO4 is illegal in your country? There is no way you can outlaw such an important industrial chemical. Buy it with the proper paper work. You won’t need much for fischer esterfication considering it is a catalyst.
Yes h2s04 needs a very very special paper work, because its used un the cocaine manufacture. You can find small dilutions for LAB propourses but they arent cheap.
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