3- Aroyl-4-methyl- -2-methylthio

Anilino-thiocarbonylamino)-4-methyl- 58 2-Arensulfonylamino- 196 5-Aroyl-2-methylthio- 132 2-(3-Arso-anilino)-4-methyl- 286 Aryl- 304... 

Lithiation of the methyl of (methylthio)benzene followed by acylation with an acyl chloride and acidification to pH 4-5 yields benzothiophene in good yields, but when aroyl chlorides are used, the mixture has to be heated in benzene. An attempted dehydration of the secondary alcohol (87.4) with hydrobromic acid led to S-demethylation and cyclization. Similar treatment of the isomeric 2-(2-methy thio-4-nitrophenyl)-l-phenylethanol gave a high yield of 6-nitro-2-phenyl-2,3-dihydrobenzo[fi]thiophene [2653]. 

A convenient base-mediated strategy to synthesize 3-aroyl-4-methyl-(or benzyl)-2-methylthio furans (tri-substituted furans) was developed through domino coupling/annulation between readily available a-oxo ketene dithioacetals and propargyl alcohols (140BC8947). 

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