Nano-TiO2: an Eco-friendly and Re-usable Catalyst for the One-pot Synthesis of β-Acetamido Ketones

β -Acetamido ketones are valuable building blocks for the preparation of β -amino ketones or β -amino alcohols such as the antibiotic nikkomycins [1] and neopolyoxines [2]. α-Acetamido ketones are obtained in the Dakin-West reaction [3] and β -acetamido ketones by the Iqbal route. In the latter, an aromatic aldehyde, an enolizable ketone and acetonitrile are condensed in the presence of acetyl chloride and a catalytic amount of an acid [4]. Recently, many catalysts such as silica sulfuric acid [5], H6P2W18O62 [6], ZnO [7], sulfated zirconia [8], some heteropoly acids [9], silicasupported H3PW12O40 [10], nano-ZnO [11], sulfamic acid [12], Sc(OTf)3 [13], SnCl2·2H2O [14], Zeolite Hβ [15], ZrOCl2 · 8H2O [16], Mg(HSO4)2 [17], and Nafion-H [18] have been applied in this one-pot reaction. However, some of these methods employ long reaction times [13] or harsh reaction conditions [5 – 7, 10]. Thus, the need for the development of new protocols is evident. TiO2 as a white pigment is used in the manufacture of paint and of surface coatings on paper and as a filler in rubber and plastics. Fine particles