Sciencemadness Discussion Board
Not logged in [Login - Register]
Go To Bottom

Printable Version  
Author: Subject: catechol
Magpie
lab constructor
*****




Posts: 5587
Registered: 1-11-2003
Location: USA
Member Is Offline

Mood: Chemistry: the subtle science.

[*] posted on 8-1-2018 at 19:24
catechol


I remember reading on this forum about making catechol using calcium bromide. This was 1-2 months ago (I think). But I can't find anything on this. I even bought 25g of Ca(Br)2 with which to make it.

Does anybody remember this synthesis?




The single most important condition for a successful synthesis is good mixing - Nicodem
View user's profile View All Posts By User
PirateDocBrown
National Hazard
****




Posts: 360
Registered: 27-11-2016
Location: Minnesota
Member Is Offline


[*] posted on 8-1-2018 at 22:00


From phenol?



Phlogiston manufacturer/supplier.

For all your phlogiston needs.
View user's profile View All Posts By User
Magpie
lab constructor
*****




Posts: 5587
Registered: 1-11-2003
Location: USA
Member Is Offline

Mood: Chemistry: the subtle science.

[*] posted on 8-1-2018 at 22:05


yes, I believe it was! It might have been in a referenced paper.



The single most important condition for a successful synthesis is good mixing - Nicodem
View user's profile View All Posts By User
PirateDocBrown
National Hazard
****




Posts: 360
Registered: 27-11-2016
Location: Minnesota
Member Is Offline


[*] posted on 8-1-2018 at 22:24


It's entirely possible to transform phenol into catechol using hydrogen peroxide. I don't know what catalyst is typically used, but it could be a halide.



Phlogiston manufacturer/supplier.

For all your phlogiston needs.
View user's profile View All Posts By User
yobbo II
Hazard to Others
***




Posts: 218
Registered: 28-3-2016
Member Is Offline


[*] posted on 9-1-2018 at 07:56


https://www.google.ie/search?q=catechol+from+phenol+site%3Aw...

One up from the bottom
View user's profile View All Posts By User
Magpie
lab constructor
*****




Posts: 5587
Registered: 1-11-2003
Location: USA
Member Is Offline

Mood: Chemistry: the subtle science.

[*] posted on 9-1-2018 at 14:57


Thanks so much yobbo II. I have a 400w source of h√ so will give this a try.



The single most important condition for a successful synthesis is good mixing - Nicodem
View user's profile View All Posts By User
Magpie
lab constructor
*****




Posts: 5587
Registered: 1-11-2003
Location: USA
Member Is Offline

Mood: Chemistry: the subtle science.

[*] posted on 9-1-2018 at 19:55


I think I have found 2 better syntheses for catechol:

One starts with guaiacol and uses 48% HBr. This is a 1941 synthesis by Taylor & Clark published in OrgSyn.

The other starts with salicylaldehyde and uses HOOH as reagent. By-product is the formate ion. This is by Dakin and is also published in OrgSyn (1941).




The single most important condition for a successful synthesis is good mixing - Nicodem
View user's profile View All Posts By User
Assured Fish
Hazard to Others
***




Posts: 174
Registered: 31-8-2015
Location: Bird land, southeast of Aus
Member Is Offline

Mood: Photodegradable

[*] posted on 9-1-2018 at 20:49


I would advise strongly against the Dakin reaction, the yields tend to suck balls, also you would first have to either prepare of get your hands on salicylaldehyde.
http://www.nrcresearchpress.com/doi/pdf/10.1139/v73-357
I have however prepared 2-aminophenol by hoffman rearangement of salicylamide followed by hydrolosis of the resulting benzoxazolone.
Unfortunately i still haven't gotten round to performing the sandmeyer reaction as getting my hands on sodium nitrite in NZ is an absolute pain in the buttox.
I followed the following prep and got close to 80% yield starting from salycilic acid, if i recall major loss was during the hoffman rearrangement.
I had an issue doing a large scale batch however (30g), during hydrolysis of the benzoxazolone i foolishly used too high of a concentration of HCl which lead to it not working at all.
A second attempt with dilute HCl worked however it was very slow. I do not know why this requires dilute HCl, if someone could enlighten me it would be much appreciated.
http://www.sciencemadness.org/talk/viewthread.php?tid=63327#...
View user's profile View All Posts By User
Magpie
lab constructor
*****




Posts: 5587
Registered: 1-11-2003
Location: USA
Member Is Offline

Mood: Chemistry: the subtle science.

[*] posted on 9-1-2018 at 21:17


OK thank you.



The single most important condition for a successful synthesis is good mixing - Nicodem
View user's profile View All Posts By User
DJF90
International Hazard
*****




Posts: 2218
Registered: 15-12-2007
Location: At the bench
Member Is Offline


[*] posted on 10-1-2018 at 08:01


Magpie, its hard to go wrong with an OrgSyn procedure. I'd say pick whichever one is most accessible to you.
View user's profile View All Posts By User

  Go To Top