Study On The Synthetic Method And Structural Characterization Of Dipyrrole Disulfides Derivatives

The work in this paper can be summarized to an unprecedented synthesis of penta-substituted dipyrrole disulfides derivatives from acyl thioformanilides, which were used as multifuctional synthons. Twenty-two dipyrrole disulfides derivatives and ten sulfides derivatives were synthesized in this paper, and the structure of all the synthesized compounds were characterized by IR, 1H NMR, 13C NMR spectrum and elemental analysis, some of them were further confirmed by MS spectrum. So far, to the best of our knowledge, there have been no reports on the synthetic application of acyl thioformanilides 1 with acetonitrile derivatives. The results of our studies, which led to an unprecedented synthesis of penta-substituted dipyrrole disulfides, are presented herein.In the first chapter, acyl thioformanilides as versatile building blocks in organic synthesis owing to their readily accessibility and good reactivity were reviewed firstly. Then it was summarized the advantages such as the convenient management, the higher productivity and the diminish of circumstance pollution by using one-pot reactions and the microwave dielectric heating in organic synthesis.In the second chapter, a sequential one-pot two-step protocol for microwave-assisted synthesis of penta-substituted dipyrrole disulfides was introduced firstly. The reactions of acyl thioformanilides with ethyl 2-cyanoacetate were envisioned in the presence of base at room temperature and the intermediates were generated in situ. Then the reaction mixtures were carried out under microwave irradiation by adding acetic acid to afford dipyrrole disulfides. Target compounds were obtained in moderate yields and simply purified by recrystallization. The novel method is an entirely new approach for novel penta-substituted dipyrrole disulfides structural motifs. The reaction heated by traditional and microwave method was compared in this chapter, compared with the traditional synthetic method, under the microwave radiation the same products were obtained with shorter reaction time and higher yield. Secondly, the reactions of acyl thioformanilides with malononitrile instead of ethyl 2-cyanoacetate were introduced. Compared with the former experiment, the reaction was preceded in only one step under lower temperature, shorter time and in higher yields.