200711-30-4Relevant articles and documents
One-pot synthesis of 2,3-disubstituted benzo[b]thiophene derivatives from 2-mercaptophenyl ketones
Kobayashi, Kazuhiro,Nakamura, Daizo,Fukamachi, Shuhei,Konishi, Hisatoshi
, p. 919 - 924 (2008/09/21)
2-Mercaptophenyl ketones have been found to react with activated alkyl bromides (BrCH2EWG's), such as bromoacetates, bromoacetonitrile, and bromomethyl phenyl ketone, in the presence of two molar amounts of sodium hydride in THF at 0 °C to affo
New routes to benzothiophenes, isothiazoles and 1,2,3-dithiazoles
Emayan, Kumaraswamy,English, Russell F.,Koutentis, Panayiotis A.,Rees, Charles W.
, p. 3345 - 3349 (2007/10/03)
4,5-Dichloro-1,2,3-dithiazolium chloride 1 condenses with active methylene compounds, such as malononitrile, barbituric acid and Meldrum's acid, to give the dithiazol-5-ylidene derivatives, such as 3,4 and 5, in modest yields. Better yields are obtained from 4-chloro-1,2,3-dithiazole-5-thione 6. Thus the thione 6 condenses with diphenyldiazomethane in a very mild version of the Barton double extrusion synthesis of hindered alkenes; this requires neither heat to extrude nitrogen nor a phosphine to abstract sulfur, to give the alkene 7 (83%) (Scheme 1). This alkene rearranges at room temperature, with loss of hydrogen chloride and sulfur, to give the benzothiophene 13 (89%) in a new thiophene ring-forming reaction (Scheme 2). The thione 6 also condenses with tetracyanoethylene oxide to give a better yield of the dicyanomethylene compound 3 (70%) (Scheme 4). Compound 3, in turn, reacts with morpholine and with chloride ions (Scheme 5) to give 3-morpholino- 19 (60%) and 3-chloro- 20 (100%) isothiazole-4,5-dicarbonitrile, in a new isothiazole ring synthesis. Mechanisms are proposed for all of these reactions.
