Über die Synthese der isomeren Ephedrine und ihrer Homologen

Abstract

lm Jahre 1887 hat der eine von uns (Nagai) in der chinesischen Droge, Ma Huang, eiii neues Alkaloid, E p h ed r i n , gefunden. Nach seinen eingehenden Untersuchungen l) ist seine Konstitution so weit aufgeklart, daB es ein Abkiimmling von Propylbenzol ist , dessen Propylkette eine 08-und eine NH.CH,-Gruppe und ein o-Methyl besitzt. Seine wichtigsten experimentellen Beweise sind folgende. Ephedrin liefert einerseits durch die Oxydation mit Kaliumpermangauat (bzw. Jod) Benzaldehyd3 (bzw. Benzoesaure), Essigsaure und Methylamin, anderseits durch Erhitzen mit Salzsaure im geschlossenen Hohr auf 160-170° neben d-Isoephedrin Benzylmethylketon und Methylamin. Iufolgedessen sollte die Konstitntion einer der beiden Formeln entsprechen:

Vasorelaxant effects of 2‐nitro‐1‐phenyl‐1‐propanol in rat aorta

“…The present study investigated the vasorelaxant effects of NPP, an intermediate in the organic synthesis of sympathomimetic drugs, such as ephedrine and norephedrine . Our findings revealed that NPP has a vasodilator profile in isolated rat aorta, with EC 50 values of around 30 μmol/L, suggesting considerable pharmacological potency for this compound.…”

“…In contrast, Figure 3c shows a rightward shift of the concentrationeffect curve of NPP when the aortic rings were pretreated with 1H- [1,2,4] oxadiazolo [4,3-a]quinoxalin-1-one (ODQ; 10 μmol/L, n=6), 11 cis-N-(2phenylcyclopentyl)-azacyclotridec-1-en-2-amine hydrochloride (MDL-12330A; 3 μmol/L, n=9), 7…”

“…Synthesized from benzaldehyde and nitroethane by Nagai and Kanao in 1929, 2‐nitro‐1‐phenyl‐1‐propanol (NPP; molecular weight, 181.2 Da; CAS no. 6343‐57‐3) is a nitro alcohol (Fig.…”

Ephedrine and Pseudoephedrine (C6–C1 Part Derived from l-Phenylalanine and Nitrogen Derived by Transamination)

“…20.4). A simple synthesis of (AE)-ephedrine and (AE)-pseudoephedrine and their subsequent resolution to the optically active varieties [9,10] are shown in Fig. 20.6.…”

Use of Acyl Migration in Separating Diastereoisomeric Amino Alcohols

“…dZ-Nor-iZ'-ephedrine was synthesized from propenylbenzene via 1-phenyl-1nitroso-2-nitropropane and l-phenyl-2-nitro-l-acetoxypropane, according to the principle of Bruckner's synthesis (4); the formation of norephedrine could not be detected. The W-benzoyl derivatives of these diastereoisomers behave differently towards alcoholic hydrogen chloride; N-benzoyl-dZ-norephedrine did not undergo acyl migration in the course of three days at room temperature, whereas N-benzoyl-dZ-nor-i/'-ephedrine yielded the calculated amount of 0benzoyl-dZ-nor-i^-ephedrine hydrochloride (5). This behavior prompted us to attempt the separation of these diastereoisomers by the acyl migration reaction.…”