The Vespiary

The Hive => Methods Discourse => Topic started by: Barium on January 10, 2003, 02:08:00 PM

Title: Aromatic iodination of phenylpropanolamines
Post by: Barium on January 10, 2003, 02:08:00 PM
p-OH-norepedrine and p-OH-ephedrine is iodinated with ethanolic solutions of iodine.

Patent GB1040736 (http://l2.espacenet.com/dips/viewer?PN=GB1040736&CY=gb&LG=en&DB=EPD)



Title: Patent Text
Post by: Rhodium on January 10, 2003, 03:50:00 PM
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.
Title: amphetamines and phenethylamines
Post by: Sunlight on January 10, 2003, 06:02:00 PM
Any oppinion about if it can work with amphetamines and phenethylamines ?
Title: By all means, it should, as long as it is a...
Post by: Rhodium on January 10, 2003, 06:08:00 PM
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 (https://www.thevespiary.org/talk/index.php?topic=6574.msg28557900#msg28557900)

(foxy2: "3,5-diiodo-4-methoxyphenethylamine", Chemistry Discourse)
for the same reaction performed on tyramine.
Title: > 50 ml of distilled water to which 140 ml...
Post by: Osmium on January 10, 2003, 07:54:00 PM
> 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...  ::)

Title: complex
Post by: Aurelius on January 10, 2003, 08:43:00 PM
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.