Premium
Synthesis of Optically Active 1‐(1‐Phenylethyl)‐1 H ‐imidazoles Derived from 1‐Phenylethylamine
Author(s) -
Mlostoń Grzegorz,
Mucha Paulina,
Urbaniak Katarzyna,
Broda Karolina,
Heimgartner Heinz
Publication year - 2008
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.200890028
Subject(s) - chemistry , imidazole , yield (engineering) , ketone , optically active , formaldehyde , medicinal chemistry , stereochemistry , organic chemistry , materials science , metallurgy
The three‐component reaction of ( R )‐ or ( S )‐1‐phenylethylamine ( 6 ), formaldehyde, and an α ‐(hydroxyimino) ketone 5 , i.e. , 3‐(hydroxyimino)butan‐2‐one ( 5a ) or 2‐(hydroxyimino)‐1,2‐diphenylethanone ( 5b ), yields the corresponding enantiomerically pure 1‐(1‐phenylethyl)‐1 H ‐imidazole 3‐oxide 7 in high yield ( Schemes 2 and 3 ). The reactions are carried out either in MeOH or in AcOH. Smooth transformations of the N ‐oxides into optically active 1‐(1‐phenylethyl)‐1 H ‐imidazoles 10 and 2,3‐dihydro‐1‐(1‐phenylethyl)‐1 H ‐imidazole‐2‐thiones 11 are achieved by treatment of 7 with Raney ‐Ni and 2,2,4,4‐tetramethyl‐3‐thioxocyclobutanone ( 12 ), respectively ( Scheme 4 ).