Microwave‐Assisted Synthesis of Sulfurated Heterocycles with Herbicidal Activity: Reaction of 2‐Alkynylbenzoic Acids with Lawesson's Reagent
作者:Salvatore V. Giofrè、Raffaella Mancuso、Fabrizio Araniti、Roberto Romeo、Daniela Iannazzo、Maria Rosa Abenavoli、Bartolo Gabriele
DOI:10.1002/cplu.201900316
日期:2019.7
The reactivity of 2-alkynylbenzoic acids toward Lawesson's reagent (LR) under microwave irradiation (300 W, 100 °C, CH2 Cl2 ) was assessed. It was found that, depending on reaction conditions, either a dithionation- or a monothionation-cycloisomerization process takes place with formation of important sulfurated heterocycles. In particular, using 1 equivalent of LR for 1 h, dithionation occurred, with
评估了在微波辐射(300 W,100°C,CH2 Cl2)下2-炔基苯甲酸对Lawesson试剂(LR)的反应性。已经发现,根据反应条件,会发生二硫代化或单硫代化环异构化过程,并形成重要的硫化杂环。特别地,使用1当量的LR 1小时,发生二硫键化,形成苯并[c]噻吩-1(3H)-硫酮或1H-异噻吩基-1-硫酮,而当量为0.5当量。在10分钟至30分钟的LR中,选择性地获得了单亚硫代的产物(苯并[c]噻吩-1(3H)-一个或1H-异硫代色素-1-酮)。该方法的区域化学输出强烈地取决于起始的2-炔基苯甲酸衍生物的取代方式。这些化合物还通过评估其对模型物种拟南芥幼苗生长和发育的植物毒性活性而被分析为潜在的除草剂。所有化合物均在不同程度上影响所监测的形态生理参数。特别是鲜重(FW)受到显着影响,ED50值在4.81-63.7μM之间。