Direct Synthesis of 2-Methylbenzofurans from Calcium Carbide and Salicylaldehyde p-Tosylhydrazones
Rugang Fu and Zheng Li*
*College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou, Gansu 730070, P. R. China, Email: lizhengnwnu.edu.cn
R. Fu, Z. Li, Org. Lett., 2018, 20, 2228-2231.
DOI: 10.1021/acs.orglett.8b00676 (free Supporting Information)
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Reactions of calcium carbide with salicylaldehyde p-tosylhydrazones or 2-hydroxyacetophenone p-tosylhydrazones provide methyl-substituted benzofuran rings in good yields in the presence of cuprous chloride as catalyst. The advantages of this method are the use of a readily available and easy-to-handle acetylene source and a simple workup procedure.
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