Method of making amphetamine
View Patent ↗A method in which a crude chlorinated product of a phenylpropanolamine, preferably prepared by reacting thionyl chloride with the phenylpropanolamine, is purified by contacting an aqueous solution of the crude product with carbon. The carbon-treated solution of the crude chlorinated product of a phenylpropanolamine is catalytically hydrogenated to the corresponding amphetamine derivative.
1. A method for making amphetamine-related products of formula (I):
where R 1 is hydrogen or a lower alkyl group, and R 2 and R 3 are independently selected from hydrogen, halogen, lower alkyl groups, lower alkoxy groups, lower alkyl groups substituted with 1 to 5 halogens, lower alkoxy groups substituted with 1 to 5 halogens, or both R 2 and R 3 , when on adjacent carbons, together constitute —O(CH 2 ) x O— where x is an integer of 1 to 4, thereby forming a ring structure fused with the phenyl group, the method comprising:
dissolving a crude chlorinated phenylpropanolamine hydrochloride product of formula (II):
where R 1 , R 2 and R 3 have the same meanings as identified above in connection with formula (I), in water to form an aqueous solution, contacting the aqueous solution with carbon, and hydrogenating the carbon-treated aqueous solution.
2. The method of claim 1 wherein the crude chlorinated phenylpropanolamine hydrochloride product of formula (II) is prepared from a phenylpropanolamine.
3. The method of claim 1 wherein the crude chlorinated phenylpropanolamine hydrochloride product of formula (II) is prepared by adding thionyl chloride to a solution of a phenylpropanolamine in an organic solvent.
4. The method of claim 3 wherein the organic solvent is toluene.
5. The method of claim 2 wherein the crude chlorinated phenylpropanolamine hydrochloride product of formula (II) is prepared by adding thionyl chloride to a solution of a phenylpropanolamine in an organic solvent.
6. The method of claim 5 wherein the phenylpropanolamine is norephedrine.
7. The method of claim 6 wherein the organic solvent is toluene.
8. The method of claim 3 wherein the phenylpropanolamine is norephedrine.
9. The method of claim 2 wherein the phenylpropanolamine is norephedrine.
10. The method of claim 6 wherein the norephedrine is selected from the group consisting of l-norephedrine, d-norephedrine and d,l-norephedrine.
11. The method of claim 8 wherein the norephedrine is selected from the group consisting of l-norephedrine, d-norephedrine and d,l-norephedrine.
12. The method of claim 9 wherein the norephedrine is selected from the group consisting of l-norephedrine, d-norephedrine and d,l-norephedrine.
13. The method of claim 6 wherein the norephedrine is l-norephedrine.
14. The method of claim 8 wherein the norephedrine is l-norephedrine.
15. The method of claim 9 wherein the norephedrine is l-norephedrine.