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Synthese von [3‐ 14 C]‐ und [Phenyl‐U‐ 14 C] Olaquindox
Author(s) -
Maul W.,
Scherling D.,
Seng F.
Publication year - 1981
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/jlcr.2580180402
Subject(s) - chemistry , aniline , quinoxaline , yield (engineering) , medicinal chemistry , nuclear chemistry , acetic acid , stereochemistry , organic chemistry , metallurgy , materials science
Olaquindox is a new feed additive.[ 14 C]Olaquindox, labelled in different positions, was needed for tracer‐studies of pharmacokinetics, biotransformation and residues in several species of animals. 2‐ [N‐(2‐hydroxethyl)‐carbamoyl] −3‐methyl‐[3‐ 14 C] quinoxaline‐1,4‐dioxide ([3‐ 14 C]Olaquindox) was synthesized from barium[ 14 C]carbonate (22 moles; 1.15 Ci) via[1‐ 14 C]acetic acid, sodium[1‐ 14 C] acetate, [1‐ 14 C] acetylchloride, ethyl [3‐ 14 C] acetoacetate and 2‐carbethoxy‐3‐methyl‐[3‐ 14 C] quinoxaline‐1,4‐dioxide with an overall yield of 10%, based on barium[ 14 C]carbonate. The radiochemical purity was better than 98% (tlc). The specific activities of three preparations were 10.5, 8.4 and 5.45 μCi/mg respectively. [phenyl‐U‐ 14 C] Olaquindox was synthesized starting from [U‐ 14 C] aniline (19.8 mmoles; 284.4 mCi). Intermediate products were N‐acetyl[U‐ 14 C]aniline, 2‐nitro‐N‐acetyl[U‐ 14 C] aniline, 2‐nitro[U‐ 14 C] aniline and [U‐ 14 C] benzofurazanoxide. The total yield was 50% as calculated for [U‐ 14 C]aniline. At calibration samples of two preparations showed specific activities of 49.5 and 11.1 μCi/mg respectively. The radiochemical purity was checked by tlc and exceeded 98%.