Abstract
In DMSO (dimethyl sulfoxide) and some other polar solvents thermal isomerization of α-, β-, γ-, δ-, and ε-BTC2) was studied. The time course of interconversion was by studied means of gas-chromatographic analysis. At 100°C more than 100 hr were required to reach an equilibrium, where α-BTC was an almost exclusive component. NaI had a catalytic effect in the reaction. The CS2-AICl3 system caused the isomerization, in some cases very rapidly, at room temperature.
Before reaching equilibrium in the thermal isomerization, convenient chances could be found to isolate δ-BTC from β, and γ-isomer, and γ-BTC from β-BTC. Possible mechanisms and intermediates are discussed.
