Synthesis of 2-chloro-4-fluoro-5-nitrophenyl ethyl carbonate

Through acylation and nitration reactions,2-chloro-4-fluoro-5-nitrophenyl ethyl carbonate was synthesized from 2-choro-4-fluorophenol,ethyl chloroformate and fuming nitric acid.Influencing factors,reaction mechanism and kinetics of acylation and nitration reactions were investigated.Proper experimental conditions for acylation reaction were found as:n(2-choro-4-fluorophenol):n(ethyl chloroformate)=1:1.06,pH 6.8—7.0,reaction temperature 25 ℃ and reaction time 2 h.The optimal nitration reaction conditions were found as:n(HNO3):n(2-chloro-4-fluorophenyl ethyl carbonate)=1:1.25,reaction time 2 h,reaction temperature 20 ℃.The purity of 2-choro-4-fluoro-5-nitrophenyl ethyl ester was 99.21% as determined by HPLC,and the total yield of 2-choro-4-fluoro-5-nitrophenyl ethyl ester based on 2-choro-4-fluorophenol was 92.95%.The molecular structure of 2-chloro-4-fluorophenyl ethyl carbonate and 2-choro-4-fluoro-5-nitrophenyl ethyl ester were exactly identified by 1H-NMR,FT-IR and elementary analysis.