Showing papers by "Farzad Kobarfard published in 2000"
TL;DR: In this paper, it was reported that a key intermediate for 2-amino-3-fluorothiophene (1), methyl 3-fluorsophyliophene-2-carboxylate (5), had been prepared by a Schiemann reaction of the 3-diazonium salt (6) in xylenes.
Abstract: It appeared that a key intermediate for 2-amino-3-fluorothiophene (1), methyl 3-fluorothiophene-2-carboxylate (5), had been prepared by a Schiemann reaction of the 3-diazonium salt (6) in xylenes. This report was not correct. Gomberg coupling products 7 with o-xylene are actually formed. We were able to prepare 5 by using special conditions for the Schiemann reaction. The hydrazide derivative of 5 failed to give 1 under Curtius reaction conditions. Two new acetamidofluorothiophene compounds were prepared using SelectfluorTM as the fluorinating agent, but no aminofluorothiophenes 1-3 or salts could be obtained by acidic hydrolysis of either amide.