# What are the possible side reactions when preparing iron(III) naphthenate?

I am trying to prepare some iron(III) naphthenate.

And the raw materials are : ferric(III) chloride, and naphthenate acid, NaOH, toluene, deionized water

Everything worked well in lab scale: final iron(III) naphthenate dark red in color and soluble in toluene was obtained easily;

However, I encountered problem when scaling it up: it seems there are undesired side reactions, the finish goods looked like black precipitation.

Is that because naphthenate acid was oxidised by Iron(III)? or is there any other side reaction when being scaled up?

The operation:

1. I first dissolve NaOH and FeCl3 into water separately;
2. add NaOH aqueous solution into naphthenate acid while stirring at about 60°C;
3. add FeCl3 aqueous solution into the soldium naphthenate solution slowly;
4. keep reaction temperature at about 80°C for a while and remove the water;
5. reflux distillation to obtain finish goods (the maximum temperature might be high)
• Are these pure raw materials? Iron(III) Naphthenate is viscous brown liquid. – user2617804 May 30 '14 at 10:14
• Yes, all materials are pure. I can obtain desired viscous brown liquid in small vessel (about 500ml); however, it failed when being scaled up to 1$\text{m}^3$; is it because of oxidation? – LCFactorization May 30 '14 at 10:47