In order to obtain
dl-ephedrine possessing therapeutic value from
dl-Ψ-ephedrine which is obtained as a by-product in synthetic procedure, experiments were carried out by the author. Application of PCl
5 to
dl-ephedrine and
dl-Ψ-ephedrine results in Walden conversion in both cases and
dl-Ψ-1-phenyl-1-chloro-2-methylaminopropane hydrochloride (I) and
dl-1-phenyl-1-chloro-2-methylaminopropane hydrochloride (II), respectively, are formed. However, application of SOCl
2 to
dl-Ψ-ephedrine results in the formation of (I). Application of AgNO
3 solution to (I) and (II) gives, in both cases, a mixture of
dl- and
dl-Ψ-ephedrine where the amount of the latter is always larger than the former. Heating (I) with NaOH solution gives
N-methyl-1-phenyl-2-methylethylene-imine (III) which, when heated with 60% H
2SO
4, undergoes hydration and ring-cleavage, and gives about an equal mixture of
dl- and
dl-Ψ-ephedrine. Application of benzoyl or acetyl chloride to (III) results in their addition with concurrent ring-cleavage to give
dl-Ψ-1-phenyl-1-chloro-2-benzoyl (or-acetyl)-methylaminopropane (IV and V).
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