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چکیده
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Nucleophilic addition to benzene derivatives with electron withdrawing groups on the ortho and para position relative to leaving group is an important strategy to synthesis of substituted benzenes [1]. We have recently developed a general method for the preparation of dimethyl (E)-2-phenoxy-2-butenedioate from the reaction of various substituted phenols with dimethyl acetylenedicarboxylate in the presence of a catalytic amount of trimethylamine solution [2]. We envisioned that an addition of primary amines to dimethyl (E)-2-(2-nitrophenoxy)-2-butenedioate 1 should give the malimide derivatives 2 [3]. Unexpectedly, however, this reaction afforded enaminocarbonyl compounds 3 and quaternary ammonium salt 4 quantitatively under solvent free conditions at 70-80oC. The structures of 3 and 4 were deduced by 1H, 13C NMR, and IR spectroscopy.
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