N-(5-氨基-2,4-二乙氧基苯基)苯甲酰胺的合成

Synthesis of N-(5-amino-2,4-diethoxyphenyl)benzamide

以2,4-二乙氧基-5-硝基苯胺(DEANB)为原料,先经酰化反应得到N-(2,4-二乙氧基-5-硝基苯基)苯甲酰胺(DEBNB),最后经还原得到蓝色基BB的同分异构体N-(5-氨基-2,4-二乙氧基苯基)苯甲酰胺(DEBAB)。DEBNB的较佳合成条件:n(DEANB):n(苯甲酰氯)=1∶1.25,丙酮和水作溶剂,K2CO3作缚酸剂,反应温度0℃,反应时间1 h,收率90.95%,HPLC纯度98.35%;产品DEBAB的较佳合成条件:Fe粉为还原剂,n(DEBNB):n(铁粉)=1∶4,水和乙醇作溶剂,反应时间5 h,反应温度80℃,收率89.93%,HPLC纯度98.96%。

Through acylation and reduction reaction,N-（5-amino-2,4-diethoxyphenyl） benzamide（DEBAB）was synthesized from 2,4-diethoxy-5-nitroaniline（DEANB）and the experimental conditions,such as materials ratio,reaction temperature and reaction time,were investigated.Proper experimental conditions for acylation reaction were found as：n（DEANB）∶n（benzoyl chloride）= 1∶1.25,H2O and CH3OH as solvent,K2CO3 as deacid reagent reaction temperature 0 ℃,reaction time 1 h,the yield of N-（2,4-diethoxy-5-nitrophenyl） benzamide（DEBNB）was 90.95% based on DEANB and the purity was 98.35% as determined by HPLC;proper reduction reaction conditions were found as：n（DEBNB）∶n（Fe）= 1∶4,H2O and C2H5OH as solvent,reaction temperature 80 ℃,reaction time 5 h,pressure of hydrogen 1.5 MPa,the yield of DEDAB was 89.93% based on DEDNB and the purity was 98.96% as determined by HPLC.The molecular structures of product and its intermediates were identified by 1H-NMR,MS and FT-IR.