Chemistry of the phenoxathiins VIII. Synthesis of 7-chlorobenzo[1″.2″:5,6:3″,4″:5′,6′] bis[1,4] oxathiino[3,2-b:3′.2′-b′]dipyridine

As a continuation of recent study on the synthesis of a bis[1,4]oxathiinodipyridine ring system, we would now like to report the preparation of 7-chlorobenzo[1″,2″:5,6:3″,4″:5′,6′]-bis[1,4]oxathiino[3,2-b: 3′,2′-b]dipyridine. Although a potentially complex reaction with several products possible, the title compound was formed exclusively, suggesting considerable mechanistic selectivity. The characterization of the product by FT-¹H-nmr as well as its mass spectral fragmentation pathways are also reported.