Gas-phase thermolysis of dialkyl polysulfides usually gives thiophene as the major product [1]. In the thermolysis of dibutyl polysulfides, a small amount (6%) of 5-methyl-1, 2-dithiole-3- thione is also formed. We have found that the major product of thermolysis of a mixture of diisobutyl polysulfides (i-C4H9) 2Sn (n= 334) or each particular polysulfide at 3503400oC is 4-methyl-1, 2-dithiole-3-thione (I). Its yield reaches 72% from diisobutyl trisulfide at 400oC. ...
