The Conversion of 5,5′-Bi(1,2,3-dithiazolylidenes) into Isothiazolo[5,4-d]isothiazoles
作者:Lidia Konstantinova、Ilia Baranovsky、Vlada Strunyasheva、Andreas Kalogirou、Vadim Popov、Konstantin Lyssenko、Panayiotis Koutentis、Oleg Rakitin
DOI:10.3390/molecules23061257
日期:——
Thermolysis of 4,4′-dichloro-, 4,4′-diaryl-, and 4,4′-di(thien-2-yl)-5,5′-bi(1,2,3-dithiazol-ylidenes) affords the respective 3,6-dichloro-, 3,6-diaryl- and 3,6-di(thien-2-yl)isothiazolo[5,4-d]-isothiazoles in low to high yields. The transformation of the 4,4′-diaryl- and 4,4′-di(thien-2-yl)-5,5′-bi(1,2,3-dithiazolylidenes) occurs at lower temperatures in the presence of the thiophiles triphenylphosphine or tetraethylammonium iodide. Optimized reaction conditions and a mechanistic rationale for the thiophile-mediated ring transformation are presented.
热解 4,4′-二氯、4,4′-二芳基和 4,4′-二(噻吩-2-基)-5,5′-双(1,2,3-二噻唑-亚基)可得到相应的 3、6-二氯、3,6-二芳基和 3,6-二(噻吩-2-基)异噻唑并[5,4-d]-异噻唑的低产率至高产率。4,4′-二芳基和 4,4′-二(噻吩-2-基)-5,5′-双(1,2,3-二噻唑亚基)在较低温度下,在亲硫剂三苯基膦或四乙基碘化铵存在下发生转化。文中介绍了优化的反应条件和亲硫剂介导环转化的机理。