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چکیده
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The reaction of nano silica with 3-chloro-propyltrimethoxysilane followed by treatment with ami-noethylpiperazine afforded nano silica-bonded aminoeth-ylpiperazine (SB-APP). The structure of the synthesized SB-APP was characterized by FT-IR, TGA, BET, SEM and elemental analysis and identified as an efficient basic catalyst for the preparation of 2-amino-4H-chromenes and 12H-chromeno[2,3-d]pyrimidine derivatives. One-pot three-component reaction of phenols, aromatic alde-hydes and malononitrile in the presence of the catalytic amounts of SB-APP afforded high yield of the correspond-ing 2-amino-4H-chromenes under mild reaction condi-tions. 12H-Chromeno[2,3-d]pyrimidines were successfully synthesized with reasonable yield by reacting the 2-amino-4H-chromenes with acetic anhydride in the same pot with-out purification of the corresponding chromene intermedi-ates. All products were characterized by FT-IR, 1H NMR, 13C NMR and MS data. The catalyst was simply recovered from the reaction mixture and reused several times without significant loss of catalytic activity.
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