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

Abstract

In this study, 2H-1,1,3,4,4-pentachloro-1,3-butadiene ( 1 ) reacted with different thiols (2-Methyl-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-thio-substituted-1-buten-3-ynes. Among them, (4-tert-butylphenyl)(1,3,4,4-tetrachlorobuta-1,3-dienyl)sulfane ( 4c ) exhibited two isomers of mono products. And, the reaction of compound ( 1 ) with 2-Hydroxythiophenol ( 2e ) in dimethylformamide in the presence of triethylamine took place formation of OH protected butadiene structure 2-((Z)-1,3,4,4-tetrachlorobuta-1,3-dienylthio)phenol ( 4e ) and ring-closed 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 different methods, mass spectrometry (GC-MS(+EI)), 1 H-, 13 C-, APT- NMR, IR and elemental analysis.