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Author Topic: Synthesis of (d-ephedrine hcl)  (Read 236 times)

XuTai10

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Synthesis of (d-ephedrine hcl)
« on: December 18, 2011, 05:53:35 PM »
Hi all.
I'm trying to develop a method of production (d-ephedrine hcl) by active amination and hydrogenation on palladium catalyst under U.S. Patent No. 7,176,332 B2, where there is a main product (l-ephedrine). During this hydrogenation to meet with several uncertainties. The resulting mixture of hydrogen, even if the reactants are not in the liquid crystalline state but it is. It is not possible, these crystals dissolve in ether but only in the water.

After dissolution of the crystalline mixture of hydrogen sever unreacted L-PAC and the rest of the mixture do synthesis using acetic acid and acetan chloride. Then mix in a vacuum, and sever the remainder of the mixture crystallizes with acetone. This creates scaly crystals with melting point 220 ° C for pure clean.

Of the total 200 g of hydrogenated L-PAC yield 45 g I in crystalline form (l-ephedrine).

Would anyone be willing to help me with this problem? Request (d-ephedrine hcl)

java

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Re: Synthesis of (d-ephedrine hcl)
« Reply #1 on: December 18, 2011, 06:14:50 PM »
.......you need l-epherdine to reduce and the final product of the amine will be the d-amine, there is an inversion occurring so you get the + enantiomer.....but if you really need + ephedrine you need to recimise it to (+,-)ephedrine then do a resolution to separate the enantiomers......java
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XuTai10

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Re: Synthesis of (d-ephedrine hcl)
« Reply #2 on: December 18, 2011, 06:29:59 PM »
I thought that I would adjust to the hydrogenation process output was flat racemic ephedrine. But I'm not sure of the quality of hydrogenation and added value (see hydrochloric acid, etc.).

XuTai10

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Re: Synthesis of (d-ephedrine hcl)
« Reply #3 on: December 18, 2011, 09:18:55 PM »
For JAVA> It is obvious, but the practical part, unfortunately, is inapplicable. With acylation I got (l-ephedrine hcl), but there should be present and pseudoephedrine hcl. Please can you direct me somewhere where I read about this more directly? Respectively, the reduction of L isomers to D isomers?

POSEIDON

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Re: Synthesis of (d-ephedrine hcl)
« Reply #4 on: December 19, 2011, 12:25:27 AM »
Look this pdfs
The chemists are a strange class of mortals, impelled by an almost insane impulse to seek their pleasures amid smoke and vapour, soot and flame, poisons and poverty; yet among all these evils I seem to live so sweetly that may I die if I were to change places with the Persian king.
— Johann Joachim

lugh

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Re: Synthesis of (d-ephedrine hcl)
« Reply #5 on: December 19, 2011, 12:54:42 AM »
The attached patent discusses the subject as well  8)
Chemistry is our Covalent Bond
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