Kanamaru H, Nishioka K, Komori H, Kawahara K
Takarazuka Research Center, Sumitomo Chemical Co., Ltd., Japan.
Radioisotopes. 1988 Jan;37(1):1-6. doi: 10.3769/radioisotopes.37.1.
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.
溴丁酰草胺是一种新型除草剂，为了进行代谢研究，分别在羰基和苯环上用碳 - 14进行标记。新戊基氯化镁（3）的14C - 羧化反应定量生成3,3 - 二甲基[1 - 14C]丁酸（4a）。4a用亚硫酰氯氯化，随后用溴进行α - 溴化反应，得到2 - 溴 - 3,3 - 二甲基[1 - 14C] - 丁酰卤（5a），5a随后与α,α - 二甲基苄胺（6a）缩合，得到[羰基 - 14C]溴丁酰草胺（1a）。从碳酸钡[14C]（2）开始，1a的总产率为76%。类似地，由α - 甲基[苯基 - U - 14C]苯乙烯（7）分三步制备的α,α - 二甲基[苯基 - 14C]苄胺（6b）与2 - 溴 - 3,3 - 二甲基丁酰卤（5b）缩合，经纯化后得到[苯基 - 14C]溴丁酰草胺（1b），产率为67%。1a和1b的比活度分别为1.38和0.781 GBq/mmol（37.2和21.1 mCi/mmol）。
