Sciencemadness Discussion Board

tetrahydrofuran synthesis

arkallic - 13-11-2012 at 02:33

Hello everyone,

forgive me for I am still a chemistry noobie.

As of recently i've been looking around on tetrahydrofuran synthesis. So I was hoping that maybe someone could help me in understanding how to do it. If you can that would be absolutely amazing!

Thanks in advance.

tetrahedron - 13-11-2012 at 02:44

just follow these four easy steps:

FURFURAL from corncobs

2-FURANCARBOXYLIC ACID from furfural

FURAN from 2-furancarboxylic acid

TETRAHYDROFURAN from furan

=D

arkallic - 13-11-2012 at 15:53

Thank you very much! At first I wasn't too happy about the continuous extraction apparatus but I found an alternative. :)

Poppy - 14-11-2012 at 13:54

Thats about the way you go, the last step is the most dificult but corncobs are worth the premisse.

tetrahedron - 14-11-2012 at 14:25

even the first one isn't a joke, i tried once but had a dismal yield. furan is pretty toxic, if you do get there.

bbartlog - 14-11-2012 at 18:30

I'd look at one of the other oxidation-based syntheses that is referenced in Org Syn when doing step 2 (furfural to 2-furancarboxylic acid). The atom economy of the Cannizzaro is obviously not so good and since the yield is 60% of theoretical (more like 50% if you do the final purification) the actual molecule-to-molecule yield is more like 25%.

arkallic - 17-11-2012 at 19:10

I've only seen two so far. The one tetrahedron showed me, and an other one where part of it is where you put furfural and sodium hydroxide in dropping funnels with a rapid stream of oxygen in more sodium hydroxide in water. and -silver oxide

So I have a few questions. When it comes to the one tetrahedron showed me, must I use a continuous extraction? If so is there a more simple way of doing things?

and as for the 2nd one, I really dont want to buy a tank of oxygen. Is there a mod that could make it so I don't have to do this? Because i'm finding that they can be a little pricey. But if I must save up for it... oh well :\ I think I can live with that haha.

Thanks again everyone!

[Edited on 18-11-2012 by arkallic]

Poppy - 18-11-2012 at 22:11

Sorry but, as far as a lazy search was done, can you people explain where the heck is oxygen coming into things in this whole process? Really

tetrahedron - 19-11-2012 at 05:10

2-FUROIC ACID from furfural (2)
Quote:
To the flask is added 250 ml. of a 2.5% solution of sodium hydroxide and a cuprous oxide-silver oxide catalyst (Note 2). In the two dropping funnels are placed, respectively, 96 g. (1.0 mole) of furfural (Note 3) and a solution of 40 g. (1.0 mole) of sodium hydroxide in 100 ml. of water. The contents of the flask are heated to about 55°, vigorous stirring is started, and a rapid stream of oxygen is bubbled through as the contents of the two funnels are added simultaneously (Note 4) to the reaction mixture at such a rate (20–25 min.) as to maintain the temperature at 50–55° (Note 5) without external heating. After the additions have been completed, vigorous stirring and passage of oxygen are continued until the temperature drops below 40° (15–30 min., depending on the rate of oxygen flow).

maybe a quantitative instead of a catalytic amount of CuO can be used instead.

why are more common oxidants such as peroxide, hypochlorite or dichromate mentioned nowhere?

[Edited on 19-11-2012 by tetrahedron]