Nitration of some 2-substituted thionaphthenes

A study is made of the nitration of thionaphthene-2-aldehyde, its diacetate, and of 2-(-nitrovinyl)thionaphthene. UV and IR spectroscopy show that nitration of thionaphthene-2-aldehyde in acetic anhydride gives a mixture of 3-nitrothionaphthen-2-aldehyde diacetate, 4-nitrothionaphthene-2-aldehyde diacetate, and 6-nitrothionaphthene-2-aldehyde diacetate in the ratios 106624, while nitration of thionaphthene-2-aldehyde diacetate gives a mixture of 3-nitrothionaphthene-2-aldehyde diacetate, 4-nitrothionaphthene-2-aldehyde diacetate, and 6-nitrothionaphthene-2-aldehyde diacetate in the ratios 363826. Nitration of 2-(-nitrovinyl)thionaphthene gives 4-nitro-2-(-nitrovinyl)thionaphthene.