Sciencemadness Discussion Board

Aniline from orange aniline dye

Random - 11-12-2010 at 04:12

I found some orange aniline dye, so I would want to make some aniline from that. Is it possible and how could I do this?

By the way, can I make aniline easily from phenol solution or can someone list some interesting syntheses with phenol?

madscientist - 11-12-2010 at 05:23

I'm not familiar with the structure of orange aniline dye, but I do doubt it's going to be cheap or easy to get aniline from that.

The easiest and most OTC route to aniline I can think of is to prepare benzamide from benzoic acid and ammonia, and to perform the Hofmann rearrangement on it with hypochlorite to yield aniline.

Random - 11-12-2010 at 06:01

How to prepare it with benzoic acid and ammonia? I read that urea can be used with benzoic acid, but I am more interested in ammonia as it's easier to get.

not_important - 11-12-2010 at 15:25

Heating ammonium benzoate will give some of the amide, reacting a simple ester such as methyl bezoate with concentrate aqueous ammonia is a bit better. The urea method is good, as urea is a common nitrogen fertiliser you might do a bit of searching.

Random - 11-12-2010 at 16:03

But then for ester I again need sulfuric acid which I don't have :(

I am thinking about boiling some urine :D (i could buy 50kg bag of urea to get it and I don't need that much of it)

not_important - 12-12-2010 at 11:20

Buy the bag, it's easier than other choices. H3PO4 will work for esterfication, as will a number of other catalysts.

If you go the ammonium salt route the yields can be greatly boosted by passing NH3 (g) over/through the reaction mix. Suspend finely powdered ammonium benzoate in tec xylene, slowly bubble NH3 through it, and heat to around 120 C - distilling off the water-xylene azeotrope.

madscientist - 12-12-2010 at 11:25

Sulfuric acid isn't hard to find (Rooto, Liquid Fire - both drain openers), nor is janitorial grade ammonia (much stronger than windex type stuff). No need for bowls of urine all over your house! :o

Random - 12-12-2010 at 15:05

I have some rust remover, I should check if it's phosphoric acid (it says corrosive). Or maybe I will try ammonium salt route.

In my country there is no sulfuric acid to buy easily :(

Random - 11-1-2011 at 11:28

Quote: Originally posted by not_important  
Buy the bag, it's easier than other choices. H3PO4 will work for esterfication, as will a number of other catalysts.

If you go the ammonium salt route the yields can be greatly boosted by passing NH3 (g) over/through the reaction mix. Suspend finely powdered ammonium benzoate in tec xylene, slowly bubble NH3 through it, and heat to around 120 C - distilling off the water-xylene azeotrope.



I just noticed, what are those other catalysts?

entropy51 - 11-1-2011 at 13:35

Quote: Originally posted by entropy51  
Sodium bisulfate, sold as "pH Down" for swimming pools, will work as a catalyst for some esterifications. Here is one example. There are others.