摘要
以磁性Fe304负载质子化过氧钨酸盐为催化剂，在不用三氟乙酸的情况下，以双氧水为氧化剂，将2，6-二甲氧基吡嗪、2，6-二氯吡嗪和2-氯-6-甲氧基吡嗪高效地氧化为其相应的氮氧化物2，6-二氨基-3，5-二硝基-1-氧吡嗪（LLM-105）。典型条件为：底物10mmol，CH3CN30mL，催化剂Fe3O4／CS／HWO0．1g（约0．1mmol），60℃分5次逐滴加入30％双氧水5mL。反应混合物溶液经萃取和柱色谱法提纯，得产物，收率一般为60％-73％。使用高斯03量化计算程序对氧化过程进行了理论计算，结果与实验数据相符。
A new catalytic system was applied to the oxidation reactions involved in the synthesis of 2,6- diamino-3,5-dinitropyrazine-l-oxide （LLM-105）, in which protonated peroxotungstate immobilized into the network of cross-linked chitosan with the superparamagnetic Fe3 04 core （Fe3 O4/CS/HWO ） was used as the catalyst. With H202 as the oxidant, good to excellent yields could be achieved with pyrazine, 2, 6- dimethoxypyrazine, 2,6-dichloropyrazine and 2-chloro-6-methoxypyrazine as the substrates without addition of trifluoracetic acid. A representative procedure for the oxidation process is as following： to 30 mL of CH3CN containing substrate（lO mmol） and Fe304/CS/HWO（0. 1 mmol, about 0. 1 g）, 30% H202 （5 mL） was added dropwisely by 5 times at 60 ~（2 temperature. The oxidation process was monitored by TLC. Product could be obtained with a yield ranging from 60% to 73%. Theoretical studies were also carried out with Gaussian 03 to evaluate the oxidation process. All of the calculated data matched well with the experimental results.
出处
《应用化学》
CAS
CSCD
北大核心
2014年第1期41-49,共9页
Chinese Journal of Applied Chemistry
基金
国家自然科学基金委员会-中国工程物理研究院联合基金资助项目(11076017)~~
关键词
过氧钨酸盐
氧化
吡嗪衍生物
LLM-105
量化计算
protonated peroxotungstate, oxidation, pyrazine derivatives, diamino-dinitropyrazine-oxide, theoretical studies
