Total Synthesis and High Performance Liquid Chromatography Analysis of Phenylethanolamine A

A simple, effective and reliable synthetic method was developed to construct beta-agonist phenylethano- lamine A（PEAA） in good yield with 4-nitrobenzyl bromide as the starting material, which underwent SN2 reaction with ethyl acetoacetate, followed by hydrolysis with concentrated HC1 and amination by Lettkart reaction to furnish 4-（4-nitrophenyl）butan-2-amine（A）. A one-pot reaction was studied to construct PEAA skeleton and reduced carbonyl with KBH4, the conditions were optimized, including reaction temperature, reaction time, solvent and the molar ratio of 2-bromo-l-（4-methoxyphenyl）ethanone（B） to A. Meanwhile, a reliable and practical high performance liquid chromography（HPLC） method with UV detector was developed after screening wavelength, chromatographic column and optimization of mobile phase. The optimal conditions of detecting PEAA were water（0.1% formic acid and 0.1% triethylamine）-methanol（volume ratio 44：56） at 278 nm with plus-C~8 column. The above synthetic method would be used to synthesize standard reference materials and advance extensive application of analytical method. In order to ensure food safety and safeguard human health, the analytical method might be used as a standard method in detection and supervision of PEAA.