However, the resulting products after purification showed considerably lower degrees of thionation, ranging from 3% (target 15%) to 42% (target 50%) (Table ). Unfortunately, we could not quantify the thionation degree via NMR spectroscopy directly from reaction controls due to overlapping signals (Figure ). In the case of 30% targeted thionation degree, extension of reaction time from 18 to 46 h increased the obtained thionation degree from 16 % to 20 %.