(Chief Bee)
11-25-03 03:51
No 473062
(Rated as: good read)
The article gives no examples of N-demethylation of secondary amines, and usually the Hypophosphorous Acid/Iodine reduction of (pseudo)ephedrine is conducted under less harsh conditions, but this may be something to bear in mind...
Hypophosphorous Acid-Iodine: An Efficient and Mild Reagent for Cleavage of N–C Bond
Ge Meng, Yan-Ping He, and Fen-Er Chen
Synth. Commun. 33(15), 2593–2598 (2003) (../rhodium/pdf /h3po2-i2.n-d
DOI:10.1081/SCC-120021978
Abstract
A mixture of hypophosphorous acid (H3PO2) and iodine in acetic acid can selectively cleave the N-alkyl bond in a variety of substituted heterocylic compounds in good to excellent yields without any damage to amide bond present in the substrates.
(Hive Addict)
11-25-03 10:59
No 473132
Rhodium can you give one or two examples of secondary amines, and also what N-demethylation would do to those theoretically? (theoretically if it happened to work using this route)
Well, I'd know what the demethylation did from looking at the starting material, but I want you to choose one yo like!
You don't need 2 Bee High to follow the goings-on @The-Hive--Just Addikted!
(Chief Bee)
11-25-03 11:02
No 473133
I inferred that amphetamine could perhaps be formed from methamphetamine (which is an N-methylated secondary amine) if either the precursor (pseudo)ephedrine or the product was demethylated.
(Hive Addict)
11-25-03 13:48
No 473163
fuck! a revelation, I didn't think that was possible, thanks!
You don't need 2 Bee High to follow the goings-on @The-Hive--Just Addikted!
(Wizard Master)
11-25-03 18:52
No 473218
Rhodium stated:
I inferred that amphetamine could perhaps be formed from methamphetamine (which is an N-methylated secondary amine) if either the precursor (pseudo)ephedrine or the product was demethylated.
The -OH reduction of the ephedrine WILL predominate completely, before demethylation occurs.
(Hive Addict)
11-26-03 04:36
No 473268
Wiz, are you saying that an ephedrine reduction using H3PO2, I2 and acetic will first reduce to methamphetamine, and then on to amphetamine?
You don't need 2 Bee High to follow the goings-on @The-Hive--Just Addikted!
(Wizard Master)
11-26-03 16:17
No 473356
Yes! BUT ONLY under VERY EXTREME reaction condition. ie. very long reflux time.
Methamphetamine has a secondary amine, and this demethylation reagent will not be very effective.
A mixture of hypophosphorous acid (H3PO2) and iodine in acetic acid can selectively cleave the N-alkyl bond in a variety of substituted heterocylic compounds in good to excellent yields without any damage to amide bond present in the substrates.
Note that the demethylation of substrates are tertiary amines.