14C-labeling of bromobutide, 2-bromo-3,3-dimethyl-N-(alpha, alpha-dimethylbenzyl)butyramide.
Bromobutide, a novel herbicide, was labeled with carbon-14 independently at the carbonyl group and the phenyl ring for use in metabolic studies. 14C-Carbonation of neopentylmagnesium chloride (3) gave 3,3-dimethyl[1-14C]butyric acid (4a) quantitatively. Chlorination of 4a with thionyl chloride followed by alpha-bromination with bromine yielded 2-bromo-3,3-dimethyl[1-14C]-butyryl halide (5a), which was subsequently condensed with alpha, alpha-dimethylbenzylamine (6a) to afford [carbonyl-14C]bromobutide (1a). The overall yield of 1a was 76% from barium [14C]-carbonate (2). Similarly, condensation of alpha, alpha-dimethyl[phenyl-14C]benzylamine (6b), which was prepared from alpha-methyl[phenyl-U-14C]styrene (7) in three steps, with 2-bromo-3,3-dimethylbutyryl halide (5b) gave [phenyl-14C]bromobutide (1b) in 67% yield after purification. The specific activities of 1a and 1b were 1.38 and 0.781 GBq/mmol (37.2 and 21.1 mCi/mmol), respectively.
Kanamaru
H
H
Takarazuka Research Center, Sumitomo Chemical Co., Ltd., Japan.
Nishioka
K
K
Komori
H
H
Kawahara
K
K
D001596:Benzylamines; D002250:Carbon Radioisotopes; D006540:Herbicides; D007553:Isotope Labeling / Q000379:methods*
D001596:Benzylamines; D002250:Carbon Radioisotopes; D006540:Herbicides; C055963:2-bromo-3,3-dimethyl-N-N-(alpha-alpha-dimethylbenzyl) butyramide