5-甲基-3-乙基-4-乙酰基-2-甲氧羰基吡咯的合成

以乙酰丙酮和丙酰乙酸甲酯为主要原料,经过亚硝化、还原和Knorr成环等反应步骤,合成了多取代吡咯化合物5-甲基-3-乙基-4-乙酰基-2-甲氧羰基吡咯。研究了乙酰丙酮用量,亚硝化反应温度以及亚硝酸钠用量等反应条件对目标化合物产率的影响,确定了最佳的合成反应条件为:乙酰丙酮和丙酰乙酸甲酯摩尔比为1.8∶1.0,亚硝化反应温度为5℃,亚硝酸钠和丙酰乙酸甲酯摩尔比为1.3∶1.0。在给定的最佳合成反应条件下目标化合物的产率可达55%。通过熔点测定、IR和1H NMR等光谱分析手段对化合物进行了表征。

Synthesis of 5-methyl-3-ethyl-4-acetyl-2-methoxycarbonyl-pyrrole

A polysubstituted pyrrole,5-methyl-3-ethyl-4-acetyl-2-methoxycarbonyl-pyrrole,was synthesized using 2,4-pentanedione and methyl 3-oxopentanoate as the main initial materials via the nitrosation,reduction and the Knorr cyclization reaction.The effects of the amount of 2,4-pentanedione,the temperature of nitrosation reaction and the amount of sodium nitrite on the yield of the target compound were studied.The optimal reaction conditions were determined:the mole ratio of 2,4-pentanedione to methyl 3-oxopentanoate is 1.8 ∶1.0,the temperature is 5 ℃ for the nitrosation reaction and the mole ratio of sodium nitrite to the methyl 3-oxo-pentanoate is 1.3 ∶1.0.The yield of the target product was up to 55% under the optimal reaction conditions.The final product was characterized using melting point measurement,IR and 1H NMR spectroscopy.