amrhamed - 15-8-2007 at 11:15
I am stuck ...
I want to know if it is feasible to use the method for synthesis of 2-AMINO-6-METHYLBENZOTHIAZOLE but using p-aminobenzoic acid instead of
p-toluidine
The method I am pointing to is in the attachments
Attachment: CV3P0076.pdf (129kB)
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Ozone - 15-8-2007 at 18:47
Nice. I have been trying to find a reasonable way to make ABTS (which is $$$ when purchased from Aldrich's "very rare chemicals" collection.
At very acidic pH the COOH will be in acid form and the amine will be quaternized. My guess is that there will be some interference which will result
in low yields and a mixture which is difficult to work up (zwitterionic crap at best).
Perhaps if you somehow protected your carboxyl group prior to rxn...
Since I'm trying to make ABTS, maybe I can do a run and find out (but, I have to find the time
).
Cheers,
O3
chemrox - 15-8-2007 at 21:36
yes @ozone, you could protect the carboxylic acid groups as esters couldn't you?
amrhamed - 15-8-2007 at 21:40
I want to know the proper method of its synthesis (From any database if u plz e.g Beilstein or scifinder)
I don't know if it is possible ( and why if not possible ?)that one can synthesize 2-AMINO-6-METHYLBENZOTHIAZOLE and follow it by oxidation of methyl
........Is there any kind of mild oxidation which will not affect the ring?)
dubei - 17-9-2014 at 23:28
I have
Dr.Bob - 18-9-2014 at 06:54
Here is a crude text dump of a search, there are too many results to filter though, but they appear to indicate that you can use either the acid or
the ester and then de-esterify. Good luck.
I attached the data dump as a file now:
42%
With bromine in methanol
T=-10 - -5°C; 2 h;
Show Experimental Procedure
WANG, YANMING; Wu, Chunying
Patent: US2009/123373 A1, 2009 ;
Location in patent: Page/Page column 14-15 ;
Synthesis of 2-aminobenzothiazole-6-carbolic Acid(2)NaSCN (65 g, 0.8 mol) was added to a suspension of commercially available 4-amino-benzoic acid (1,
100 g, 0.73 mol) in MeOH followed by the addition of Br2 (38 ml, 0.73 mol) in portions. The above solution was allowed to cool to -10° C. and stirred
for 2 h while keeping the inner temperature below -5° C. The precipitate was then filtered and suspended in 350 ml of 1 M HCl. The suspension was
heated to reflux for 30 min. After immediate filtration, 150 ml concd HCl was added to the hot filtrate to give 70 g (yield 42percent) of
2-amino-benzothiazole-6-carboxylic acid (2) (as a white solid), which was dried and used without further purification.
[Edited on 18-9-2014 by Dr.Bob]
Attachment: 2-aminobenzothiazole-6-carbolic Acid.txt (24kB)
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