odin (Stranger)
12-11-02 14:50
No 388392
      Precursors from azo dyes?  Bookmark   

Azobenzene molecule can be reduced to hidrazobenzene and then further to aniline with any method used in reduction of nitro compounds (ex. Fe/HCL, LAH) (OTC aniline).
C6H5-N=N-C6H5 >(H2)> C6H5-NH-NH-C6H5 >(H2)> 2C6H5-NH2
The same reaction  can be applied on substituted azobenzenes like for example                                                  p-N,Ndimetilaminoazobenzene, but then the products would bee aniline and p-N,Ndimetilaminoaniline.

The question is will this work on 3,4-dihydroxiazobenzene (I have seen this dye somewhere, but can’t remember, maybe in Zollinger’s Dyes and pigments). Product of reduction would be 3,4-dihidroxyaniline, can this molecule be methylated to give benzodioxole with amino group, or better substitute amino group of amino-pyrocatehol with halogen (bromo-) in Sandmeyer’s fashion, and then methylate product to get bromo-benzodioxole (Safrole precursor).
All azo dyes are completely unwached chems that cea be ordered from chem supply by anybody, some of them contain indole molecules.
All of this could be shit if so flame me!
12-12-02 19:29
No 388811
      Somebody, anybody!  Bookmark   

Some refs. first toughts, anything?
(Stranger / Eraser)
12-14-02 00:49
No 389238
      OK, some comments: The reduction of azobenzenes ...  Bookmark   

OK, some comments:

The reduction of azobenzenes shouldn´t be a problem, i have some procedures around, using SnCl2 and sodium bissulfite, i think. If you want me to post them just ask.

As to the rest of your idea I think that the aniline group would react with DXM in the methylenation reaction so maybe the way to go is the sandmeyer reaction.

All this sounds like it´s too much work just to get to bromobenzodioxole, wich would require a grignard reaction with allyl halide to go somewhere interesting.

And the biggest problem with the route from vanillin or eugenol wich, for the ones without access to DMSO,DMF or PTC´s, is the methylenation is still required in the route you propose.

Personally I think this might be a better OTC way to benzoquinone via aniline or other subtituted anilines and KCr2O7 than to safrole. But If you have all the necessary reagents for the methylenation then nevermind my ramblings and just go on with it.

EDIT: Maybe you can forget the sandmeyer and use this procedure http://www.orgsyn.org/orgsyn/prep.asp?prep=cv5p0139 (referenced from rhodium´s page) to go straight from 3,4-dihidroxyaniline to protocatechuic aldehyde.
12-14-02 14:09
No 389428
      Reagents  Bookmark   

So, you are suggesting to transformate amino group to aldehide via diazonium ione , and after that methylenation of product to get piperonal. It seems to me that options are allyl-bromide or nitro-ethane, both unavailable to me. (I can get etil-amine, but have no excuse(what can I say???) –word about oxidation!)
I can prepare piperonal from pepper so the idea seems useless.
This dye is used in my college org. lab. For practicing column cromatography, and from ther the idea comes.

Please post procedure for azobenzene reduction,
And Thanks
(Stranger / Eraser)
12-15-02 22:10
No 389734
      you are suggesting to transformate amino group to ...  Bookmark   

you are suggesting to transformate amino group to aldehide via diazonium ione , and after that methylenation of product to get piperonal

Not necessarily. I think you can use the sandmeyer reaction, as you said in your first post, to get bromobenzodioxole. But, without an allyl halide you can´t do anything with it(unless I am forgetting something).

From piperonal there´s also the possibility of using the darzen´s condensation(or whatever it´s called) posted by Barium.

For OTC preparation of allyl iodide you can try this: Post 357095 (Captain_Mission: "somewhat off-topic...", Chemistry Discourse)

I´ll be back in a few days with the reduction procedures. 
(Stranger / Eraser)
12-16-02 21:40
No 390052
      Hope this helps...  Bookmark   


5g ofbeta-aminonaphtol orange are dissolved in 50ml of H2O. To the boiling orange liquid is added a solution of 12g of SnCl2 in 30ml HCl(d=1,19). With a vigorous reaction the mixture start to loose color. After some minutes it is completely colorless. The reaction mixture is cooled to precipitate the aminonaphtol hydrchloride, wich is filtered, washed with dillute HCl, alcohol and, finally, ether.
beta-aminonaphtol is separated from the aqueous solution of the hydrochloride by addition of sodium acetate in the form of needles.
With oxidants like chromic acid beta-naphtoquinoe is formed(Ber.,XXVII,3076).

Sodium Bissulfite(Ber.,39,3561)

To a hot solution of 5g beta-naphtol orange in 50ml H2O, concentrated sodium bissulfite solution is added, in small amounts, until the orange/red liquid is almost completely colorless. Slightly colored beta-aminonaphtol precipitates. According to the purity of the sodium bissulfite, 5 to 10g are used. After cooling, the formed aminonaphtol is separated by filtration, washed with water, and dried in plate of pourous pot. 

The workup might need some changes if the properties of 3,4-dihydroxyaniline differ from the substance they get. Maybe not, i don´t know. 
12-16-02 23:47
No 390075
      Too long and comlicated  Bookmark   

I think that the workup will definetly bee diferent. All thig seems to comlicated as you said at the bigining. Too much work for bromo-benzodioxole. Much more promising is route from piperonal. Etilamine can be prepared from propionamide. what do you thik can NaOBr be substituted with NaOCl.
And somethig off topic: At the Rhodiums site  ther is a  OTC synth of MMDA from myristicin via I-myristicin. Can this procedure bee aplyed on the other propenylbenzenes (apiole, dillapiole...)if not why?
Thanx for refs. and general help