Phenylhydrazine

ApprenticeCook · DILLIGAF

This is an extreme synthesis from very basic precursors, feel free to jump in from any point if you have access to the appropriate precursor at that stage...

Ok, here we go... please any comments, tell me if somethings wrong, this is a late night rambling Confused

Toluene --> KMnO4 --> Benzoic Acid
Benzoic Acid + Ethanol --> H+ --> Ethyl Benzoate
Ethyl Benzoate + NH3 --> -EtOH --> benzamide
benzamide + NaOBr --> Hofmann Reaction --> Aniline
Aniline + HNO2 --> benzenediazonium
benzenediazonium + sodium hydrogen sulphite + Hydrochloric acid --> Fischer Phenylhydrazine Synthesis --> Phenylhydrazine

Like i said its really long winded so if you have access to aniline just jump in at that step.... i dont even know if half of it makes sense little alone works so ill wait for comments.... but for now. im going to bed, night all!

-AC

Dr.Bunsen · Thu Mar 24, 2005 3:15 am

You can get benzamide directly from benzoic acid if you heat it with urea and phosphoric acid (DE 869639).
You might use sodium hypochlorite instead of NaOBr.

Esplosivo · Fri Mar 25, 2005 1:36 pm

Or you could get benzamide from benzoic acid dircet by reaction of the benzoic acid with ammonium carbonate (ammonia solution should work) and then heating the ammonium salt formed between 100 - 200 deg celcius, giving a good yield of benzamide.

mk-1 · Sat May 21, 2005 7:28 pm

Hi AC, could you provide mol quantities for the reaction of aniline with HNO2, as well as for the Fischer Phenylhydrazine synthesis? Maybe some refs?

ApprenticeCook · DILLIGAF

its a reaction well covered in merck and many other journals, google it.
And you dont need a ref for most of the steps, simple chemistry till you get to the hoffmann and Fischer steps, both as i said, are well covered elsewhere, have a look around.

-AC

stooge · Sat Jun 11, 2005 2:34 am

hahas · Sat Jun 11, 2005 5:07 am

as the patent hints, phosphoric acid is not really necessary. 60% yields are supposedly obtainable without it by heating equimolar amts @ 200-230C for an hour. it is a general reaction and gives better yields with acetic or formic acids.

another possible route to benzamide would be the old-fashioned heating of Na benzoate with NH4Cl in sealed tubes. the article that i saw this in did not mention the yield, i might just give this a try to find out. this also works with the acetate (=40%), don't know about the formate.

you would have to first chlorinate your benzoic acid (or benzaldehyde) in order to get benzamide on addition of NH4OH.

fern10 · Thu Jun 23, 2005 5:26 pm