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Enaminone‐Based Synthesis of Dipodazine Derivatives
Author(s) -
Wagger Jernej,
Bevk David,
Meden Anton,
Svete Jurij,
Stanovnik Branko
Publication year - 2006
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.200690026
Subject(s) - chemistry , racemization , piperazine , yield (engineering) , hydrochloride , stereochemistry , organic chemistry , metallurgy , materials science
A series of racemic dipodazine analogues 9 were prepared in 22–80% yield from (3 Z ,6 RS )‐3‐[(dimethylamino)methylidene]‐6‐methyl‐1‐(phenylmethyl)piperazine‐2,5‐dione ( 7 ) ( Scheme 1 ), which was prepared in four steps from ( RS )‐alanine methyl ester hydrochloride. The preparation of nonracemic 7 from ( S )‐alanine methyl ester hydrochloride failed, since the introduction of the enamino functionality at position 3 of the precursor 6 was accompanied by almost complete racemization.