Synthesis of (Thio)substituted -1,3-Butadienes and -Butenynes

Abstract

In this study, 2H-1,1,3,4,4-pentachloro-1,3-butadiene (1) was reacted with different thiols (2methyl-2-propanethiol 2a, benzyl mercaptan 2b, 4-tert-butylbenzenethiol 2c, 4-nitrothiophenol 2d) in ethanol in the presence of NaOH to afford mono-thio-substituted-1,3-butadienes and mono-and tris-thiosubstituted-1-buten-3-ynes. Among them, (4-tert-butylphenyl)(1,3,4,4-tetrachlorobuta-1,3dienyl)sulfane (4c) exhibited two isomers of mono products. Moreover, the reaction of compound (1) with 2-hydroxythiophenol (2e) in dimethylformamide in the presence of triethylamine took place the formation of OH-protected butadiene structure 2-((Z)-1,3,4,4-tetrachlorobuta-1,3-dienylthio)phenol (4e) and ringclosed butadiene structure (E)-2-(2,3,3-trichloroallylidene)benzo[d][1,3]oxathiole (6), together and with two isomers of each. Their structures identified on the basis of GC-MS(+EI) analysis with different retention times (RT). Characterization of the synthesized compounds was done using several methods, mass spectrometry (GC-MS(+EI)), 1 H-, 13 C-, APT-NMR, FTIR and elemental analysis.