Synthesis and Crystal Structure of 4,7-bis (2-thienylethynyl)-2,1,3-benzothiadiazole †

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The reaction did not proceed smoothly. 4% of a mono-coupling compound was also isolated as a by-product. In the reaction, the catalytic activity disappeared within 2 h and the starting materials were not consumed completely, though we searched various experimental conditions. This finding may be ascribed to catalytic poison effect of 2,1,3-benzothiadiazole unit.

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