Thiophenes, 2-phenyl-, nitration

Thienylthioethanols were obtained in high yields by the reaction of thiophen-2-thiols with ethylene oxide.The reaction of 2,4-dinitro-3-bromothiophen with sodium dimethylthiocarbamate or sodium t-butyl-trithiocarbonate yielded (142). Decomposition of (142b) in glacial acetic acid led to a mixture of (143) and (144) in moderate yield. The reaction of thiophen-3,4-dithiol with phosgene chloride, followed by nitration, gave (145). The reaction of thiophen-2-thiol with p-(methylsulphonyl)bromo-benzene was used for the preparation of 2-thienyl p-(methylsulphonyl)phenyl sulphide. 

Olah and Kuhn reported that thiophene forms nitrothiophene in 91% yield on nitration with NOJBFJ [17], while the nitration of furan results in a 14% yield of nitrofuran. 3-Nitro-6-phenyl-2-pyridone has been obtained in 40% yield by the nitration of 6-phenyl-2-pyridone with NO2 BF4 [75],... 

Contrary to benzo[b]thiophen, benzo[b]selenophen is acylated at position 2. 2-Bromobenzo[b]selenophen, prepared from the 2-lithium derivative and bromine, is acylated at position 3, and from this derivative the 3-isomers could be synthesized. A large number of 2- and 3-aroylbenzo[b]seleno-phens were synthesized, either by Friedel-Crafts reaction of benzo-[bjselenophencarboxylic acid chlorides and benzenes or from benzol bjselenophens and benzoic acid chlorides. Also the reaction between Grignard reagents and nitriles was used for the synthesis of aroylbenzo[b]selenophens. 4,S-Diaminobenzo[b]selenophen has been synthesized via nitration of 5-aminobenzo[b]selenophen or via the reaction of the diazonium salt derived from the S-amino-derivative with p-sulphanilic acid. From the diamino-derivative, several fused benzo[b]selenophens, e.g. (525), (526), and (527), were prepared. Reaction of the phenyl-... 

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