Abstract

SYNTHESIS OF NOVEL THIOSEMICARBAZIDE DERIVATIVES OF DISUBSTITUTED N-ARYLMALEIMIDES.

Sunita A. Chaudhari (Patil)*, Vasant M. Patil, Nilesh Patil, Kiran Gosavi, Keshav Mahale, Sambhaji V. Patil and Madhukar N. Jachak

Abstract

Herein we reported the synthesis of Thiosemicarbazide derivatives of disubstituted N-arylmaleimides. Maleimides are an important class of substrates for biological and chemical applications. The compound 1 were reacted with bromine in DMF to obtained the dibromosuccinimides 2 The compound 2 react with pyrrolidine, piperidine and morpholine as a base followed dehydrohalogenation to obtained monobromo compound; instead, complex mixtures of with unreacted dibromosccinimide 3a-c were obtained through common enaminone intermediate. Installation of an amino functionality at C-3 position in 3a-c should increase nucleophilicity at C-4 position. Thus Vilsmeier Haack formylation of 3a-c at 0-50C afforded compound 4a-c with good yield. Thus condensation of 1-(4-chlorophenyl)-2,5-dihydro- 2,5-dioxo-4-(piperidin-1-yl)-1H-pyrrole-3-carbaldehyde 4 with thiosemicarbazide in ethanol in presence of acetic acid furnished orange colour solid 5 with good yield. All the synthesized compounds were characterized by spectral and analytical methods (IR, 1H NMR, 13C NMR, Mass Spectroscopy and elemental analysis).

Keywords: Malieimide, pyrrolidine, piperidine, morpholine and Thiosemicarbazone.