摘要
由乙酰乙酸乙酯、甲酸乙酯及丁酮等原料经过肟化、Claisen缩合、还原缩合成环得到2-乙氧羰基-4，5-二甲基·吡咯（7），溴化生成2-乙氧羰基-3-溴4，5-二甲基-吡咯（8），最后经过甲酰化反应得到目标产物2-乙氧羰基-3-溴4-甲基-5-甲酰基-吡咯（9）。研究了反应条件对化合物7的合成反应的影响，确立了最佳反应条件为：pH值为3．8，锌粉与反应原料（化合物1）的摩尔比2．8：1，反应温度90～95℃，产率达到59．9％。同时就溴化反应中的溶剂以及甲酰化反应中的氧化剂对两类反应的影响分别进行了研究，结果表明溴化反应的最佳溶剂为四氯化碳，反应产率达到86．7％，甲酰化反应的最佳氧化剂为硝酸铈铵，产率达到89．3％。合成产物的结构经化合物的元素分析、精确质量数、^1H NMR、IR和GC—MS测试得到了表征。
2-Ethoxycarbonyl-4,5-dimethyl-pyrrole（7） was prepared from ethylacetoacetate, ethyl formate and methyl ethyl ketone via oximination, Claisen condensation, and reductive condensation. The bromization of compound 7 gave 2-ethoxycarbonyl-3-bromo-4,5-dimethyl-pyrrole（8） , which could be transferred to 2-ethoxycarbonyl-3-brome-4-methyl-5-formyl-pyrrole（9） by the formolation. In the synthesis reaction of compound 7, its yield was maximum when pH, the mole ratio of zinc to compound 1 and reaction temperature were set as 3.8, 2.8：1 and 90～95℃, respectively. The effects of solvent on the bromization reaction and oxidant on the formolation reaction of the target product were studied. The results show that the optimum solvent for the bromization reaction and the optimum oxidant for the formolation reaction of the target product were carbon tetrachloride and ceric ammonium nitrate, and their yields were 86.7% and 89.3% respectively. The structures of the compounds were characterized by elemental analysis, accurate mass, ^1H NMR, IR and GC-MS.
出处
《应用化学》
CAS
CSCD
北大核心
2006年第7期798-802,共5页
Chinese Journal of Applied Chemistry
