Phosphotungstic acid supported on functionalized graphene oxide nanosheets (GO-SiC3-NH3-H2PW): Preparation, characterization, and first catalytic application in the synthesis of amidoalkyl naphthols

Grafting of 3-aminopropyltriethoxysilane (APTS) on graphene oxide (GO) nanosheets followed by reaction with phosphotungstic acid (H3PW12O40, denoted as H3PW) gave a new functionalized GO which was characterized using FT-IR, FESEM, EDX, EDX elemental mapping and ICP-OES techniques. The catalytic activity of this nanomaterial containing phosphotungstic counter-anion H2PW12O40¯ (H2PW) which was denoted as GO-SiC3-NH3-H2PW was probed in the synthesis of amidoalkyl naphthols through the one-pot, three-component reaction of β‐naphthol with various aromatic aldehydes and acetamide. The results showed a significant catalytic performance of the catalyst for this transformation in ethanol as solvent at reflux temperature, giving the corresponding products in high yields. In addition, the nanocatalyst could be easily recovered from the reaction mixture and reused many times with no significant loss of its catalytic activity.