4-氨基-2,6-二甲氧基嘧啶的绿色合成工艺研究

Study on Green Synthesis of 4-Amino-2,6-Dimethoxypyrimidine

本文开发了以4-氨基-2,6-二羟基嘧啶钠盐(ADHP-Na)为反应原料,以碳酸二甲酯(DMC)为绿色甲基化试剂一步合成4-氨基-2,6-二甲氧基嘧啶(ADMP)的新工艺。通过单因素实验和正交实验研究了催化剂加入、相转移催化剂用量、固体碱催化剂碳酸钾用量、反应温度和反应时间等因素对甲基化反应性能的影响。结果表明,当反应温度为130℃,反应时间为10 h,以K2CO3为催化剂,十六烷基三甲基溴化铵(CTAB)为相转移催化剂,n(ADHP-Na)∶n(CTAB)∶n(DMC)∶n(K2CO3)=1∶0.1∶7∶0.8时,ADHP-Na转化率为59.5%,ADMP收率为40.0%。同时,FT-IR和1H NMR表征证实合成产物为ADMP,并且探究了可能的O-甲基化反应机理。本工艺的成功开发可完全避免含磷废水的产生,为ADMP的绿色合成提供了一条可行性路径。

Novel synthesis process of 4-amino-2,6-dimethoxypyrimidine(ADMP)with 4-amino-2,6-dihydroxypyrimidine sodium salt(ADHP-Na)as raw material and dimethyl carbonate(DMC)as green methylation reagent was developed.Through single factor experiments and orthogonal experiments,the effects of the types of raw materials,the amount of phase transfer catalyst,the amount of the solid alkali catalyst potassium carbonate,the reaction temperature and time on the methylation performance were investigated.The results show that the ADHP-Na conversion was 59.5%and the ADMP yield was 40.0%when the reaction temperature was 130℃,time was 10 h,K2CO3 is used as catalyst,and cetyl trimethyl ammonium bromide(CTAB)as the phase transfer catalyst,n(ADHP-Na)∶n(CTAB)∶n(DMC)∶n(K2CO3)is 1∶0.1∶7∶0.8.FT-IR and 1H NMR confirmed that the final product was ADMP.Furthermore,the possible O-methylation reaction mechanism was proposed.The successful development of this process can completely avoid the generation of phosphorus-containing wastewater,and provides a feasible path for the green synthesis of ADMP.