ABSTRACT
Thermal rearrangement of a number of 2-(4′-aryloxybut-2′-ynylthio)-thiochromen-4-ones in refluxing chlorobenzene in the presence of catalytic amounts of 4-toluenesulfonic acid afforded 3-aryloxymethyl-2-methylthieno[2,3-b]thiochromen- 4-ones in 55–62% yields.
ACKNOWLEDGMENT
We thank the CSIR (New Delhi) for financial assistance. One of us (SKG) is grateful to CSIR (New Delhi) for a fellowship.