Premium
N.C.A. 11 C‐labelling of benzenoid compounds in ring positions: synthesis of 3‐nitro‐[3‐ 11 C]toluene and 4‐nitro‐[4‐ 11 C]toluene and their corresponding toluidines
Author(s) -
Mäding P.,
Steinbach J.
Publication year - 1998
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(199807)41:7<647::aid-jlcr114>3.0.co;2-5
Subject(s) - chemistry , toluene , nitro , nitro compound , labelling , nuclear chemistry , radiochemistry , medicinal chemistry , organic chemistry , alkyl , biochemistry
The paper describes the syntheses of n.c.a. 3‐nitro‐[3‐ 11 C]toluene ( 3a ) and 4‐nitro‐[4‐ 11 C]toluene ( 3b ) by reaction of nitro‐[ 11 C]methane ( 1 ) with 5‐dimenthylamino‐2(or 3)‐methyl‐penta‐2,4‐dienylidene‐dimethylammonium tetrafluoroborate ( 2a or 2b ) in the presence of BuLi, utilizing the synchronous six‐electron cyclization of hexatriene systems into aromatics. Starting from 1 , 3a and 3b were prepared in a radiochemical purity of about 87% and 78% and with a mean specific radioactivity of 1 Ci/μmol (37 GBq/μmol) within 10 min. Related to 1 , the reproducible radiochemical yields of 3a and 3b (decay‐corrected) were 85±5% and 75±5%. Reduction of 3a and 3b by heating the above reaction mixture with aqueous Na 2 S produced m‐[1‐ 11 C]toluidine ( 7a ) of a radiochemical purity of about 82% and p‐[1‐ 11 C]toluidine ( 7b ) of a radiochemical purity of about 68%. The reproducible radiochemical yields of 7a and 7b (decay‐corrected) in relation to 1 were 78±5 and 65±5%, the synthesis time from 1 was 21 min and 16 min. © 1998 John Wiley & Sons, Ltd.