Synthesis of Tris(Arylthio)-1,3-Butadienes by Nucleophilic Vinylic Substitution of Polyhalogenated Nitrodienes and Structural Elucidation of the Products

Abstract

The reactions of polyhalo-2-nitro-1,3-butadiene with naphthalene-2-thiol and 4-methylbenzenethiol lead to highly functionalized poly(arylthio)-2-nitro-1,3-butadienes. The novel 4,4-dichloro-1,1,3-tris(2-naphthylthio)-2-nitro-1,3-butadiene (5a) and the known 4,4-dichloro-1,1,3-tris(4-methylphenylthio)-2-nitro-1,3-butadiene (5b) were synthesized by vinylic substitution of 1,1,3,4,4-pentachloro-2-nitro-1,3-butadiene with naphthalene-2-thiol and 4-methylbenzenethiol, respectively. X-ray crystal structure analyses of tris(arylthio)-2-nitro-1,3-butadienes are quite rare in the literature. Both 5a and 5b crystallize in the monoclinic space group P21/c with a = 10.5068(3) angstrom, b = 19.2468(7) angstrom, c = 15.0354(6) angstrom, Z = 4 for 5a and a = 10.7087(5) angstrom, b = 19.3315(7) angstrom, c = 12.8395(5) angstrom, Z = 4 for 5b. The structures have been solved by direct methods (SIR92) and refined to the residual index R-1 = 0.053 for 5a and R-1 = 0.048 for 5b. The structure of 5a was also characterized by NMR, mass and FTIR spectroscopy.