Cyclocondensation of [1-Cyano-2-(methylsulfanyl)vinyl]triphenylphosphonium Iodide with Amidine Nucleophiles

Author: Smolii O.   Muzychka L.   Chernega A.   Drach B.  

Publisher: MAIK Nauka/Interperiodica

ISSN: 1070-3632

Source: Russian Journal of General Chemistry, Vol.75, Iss.4, 2005-04, pp. : 527-532

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Abstract

The substituted vinylphosphonium salt (E)-MeSCH=C(CN)P+Ph3I readily cyclizes under the action of benzamidine and 3-amino-s-triazole, but it does not enter cyclocondensation with 2-aminopyridine. The structure of the cyclization product with 3-amino-s-triazole was confirmed by its transformation to 7-imino-6-(triphenylphosphoranylidene)-6,7-dihydro-s-triazolo[1,5]pyrimidine which was identified by X-ray diffraction. This stabilized ylide and its analogs proved useful starting materials for regioselective syntheses of 2-R-4-alkyl-4,7-dihydro-s-triazolo[1,5-a]pyrimidin-7-ones.