Ester recommendations (1 Viewer)

[carrotsss]

I’m doing the esterification prac in class and we get to pick which one we do, does anyone have any recommendations for esters which work well? Last time it didn’t really work well because we accidentally used a tertiary alcohol lol

 

[wizzkids]

Are you going to do a full reflux reaction to produce a pure ester, or are you just going to react in a test tube and describe the odour of the ester?

 

[carrotsss]

Are you going to do a full reflux reaction to produce a pure ester, or are you just going to react in a test tube and describe the odour of the ester?

Full reflux reaction

 

[wizzkids]

OK, full refluxing is a slow process. Make sure you do a proper risk assessment on the flammability of the chemicals. Make sure you have permission to leave the apparatus overnight, because to get a reasonable yield you are going to need 12 hours refluxing time. Make sure you have permission to use the fume closet for this amount of time.
Have a go at pineapple flavour (ethyl butanoate) because it has a really distinctive smell. The reagents are reasonably cheap and common. It gives a reasonable yield if you use an excess of the butanoic acid, like about 3:1 volumes of the carboxylic acid to the alcohol.

 

[carrotsss]

OK, full refluxing is a slow process. Make sure you do a proper risk assessment on the flammability of the chemicals. Make sure you have permission to leave the apparatus overnight, because to get a reasonable yield you are going to need 12 hours refluxing time. Make sure you have permission to use the fume closet for this amount of time.
Have a go at pineapple flavour (ethyl butanoate) because it has a really distinctive smell. The reagents are reasonably cheap and common. It gives a reasonable yield if you use an excess of the butanoic acid, like about 3:1 volumes of the carboxylic acid to the alcohol.

Cheers

We’re only doing it in a double period unfortunately and we don’t have any butanoic acid, would ethyl propanoate work similarly well?

 

[wizzkids]

Yes, ethanol with propanoic acid will yield an ester with a fruity odour like pineapples. This ester will have a boiling point of 99^oC. Use an excess of the propanoic acid. Keep the heating mantle or the hot water bath at about 60 - 70^oC. If you run short of time, then raise the temperature. You will start noticing the odour after about 1 hour.