Aromatic iodination of phenylpropanolamines

[Barium]

p-OH-norepedrine and p-OH-ephedrine is iodinated with ethanolic solutions of iodine.

Patent GB1040736

[Rhodium]

British Patent 1,040,736

EXAMPLE 1

2.3 g of para-hydroxynorephedrine are dissolved in 5 ml of water to which are added 25 ml of NH₄OH (d=0.90). A solution of 5.78 g of iodine in 50 ml of 95% ethanol is added, while stirring, over a period of 45 min. The formed 1-(4-hydroxy-3,5-diiodo-phenyl)-2-aminopropanol becomes insoluble in the course of the reaction. The precipitate, separated out by filtration, is washed with cold distilled water and then purified by dissolving it in a sodium hydroxide solution followed by precipitation by means of a current of CO₂ to give the product in the form of the free base, mp 212°C.

EXAMPLE 2

4.35 g (20 millimoles) of para-hydroxyephedrine hydrochloride are dissolved in 50 ml of distilled water to which 140 ml of NH₄OH are added (d=0.90). A solution of 11.43 g (90 millimoles) of iodine in 150 ml of 95% ethanol is added, while stirring, over a period of time of 45 min. The 1-(4-hydroxy-3,5-diiodophenyl)-2-(methylamino)-propanol becomes insoluble in the course of the reaction. The precipitate, which is separated out by filtration, is washed with cold distilled water and then purified by dissolving it in a sodium hydroxide solution followed by precipitation by means of a current of CO₂. mp 186°C.

[Sunlight]

Any oppinion about if it can work with amphetamines and phenethylamines ?

[Rhodium]

By all means, it should, as long as it is a 4-hydroxy derivative. There is no reason to believe that an aliphatic alcohol on the side chain should modify the reactivity at all. Also see

Post 285579

(foxy2: "3,5-diiodo-4-methoxyphenethylamine", Chemistry Discourse) for the same reaction performed on tyramine.

[Osmium]

> 50 ml of distilled water to which 140 ml of NH4OH are
> added (d=0.90). A solution of 11.43 g (90 millimoles) of
> iodine in 150 ml of 95% ethanol is added,

I'm not sure I want to filter that precipitate...  

[Aurelius]

That complex is stable to a degree warranting only careful consideration of the material.  if you keep in wet with Ammonia solution and dispose of it in a safe place (outside away from anything important) everything should be fine.  let it dry for about an hour outside, then start chucking pebbles at it.   fun stuff.