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N.C.A. 11 C‐labelling of benzenoid compounds in ring positions: [ 11 C]anisole derivatives
Author(s) -
Mäding P.,
Steinbach J.,
Johannsen B.
Publication year - 1997
Publication title -
journal of labelled compounds and radiopharmaceuticals
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.432
H-Index - 47
eISSN - 1099-1344
pISSN - 0362-4803
DOI - 10.1002/(sici)1099-1344(199707)39:7<585::aid-jlcr1>3.0.co;2-7
Subject(s) - anisole , chemistry , yield (engineering) , nitro , medicinal chemistry , aromatization , tetrafluoroborate , organic chemistry , catalysis , alkyl , materials science , ionic liquid , metallurgy
The synthesis route to n.c.a. 3‐nitro‐[3‐ 11 C]anisole ( 3 ) by use of the principle of synchronous six‐electron cyclization of hexatriene systems into aromatics is described and discussed. Nitro‐[ 11 C]‐methane ( 1 ) reacts with the prepared precursor 5‐dimethylamino‐2‐methoxy‐penta‐2,4‐dienylidene‐1‐dimethylammonium tetrafluoroborate ( 2b ) in the presence of BuLi to form 1‐dimethyl‐amino‐4‐methoxy‐6‐nitro‐[6‐ 11 C]hexatriene ( IA , IB ), followed by cyclization/ aromatization into 3 . Starting from 1 , 3‐nitro‐[3‐ 11 C]anisole of a radiochemical purity of about 65% and a mean specific radioactivity of 1 Ci/μmol was obtained within 10 min. Related to [ 11 C]CH 3 NO 2 , the reproducible radiochemical yield of 3 (decay‐corrected) was 60±5%. Reduction of 3 by heating the above reaction mixture with aqueous Na 2 S gave 3‐amino‐[3‐ 11 C]anisole ( 4 ) of a radiochemical purity of about 50%. The reproducible radiochemical yield of 4 (decay‐corrected) in relation to 1 was 45±5%, the synthesis time from 1 was 16 min. © 1997 John Wiley & Sons, Ltd.