NaHSO4•H2O as an efficient and eco-friendly catalyst for the one-pot multicomponent synthesis of β-acetamido ketones under mild and heterogeneous conditions

General Papers ARKIVOC 2008 (ii) 134-140 Scheme 2 Table 1. Preparation of ß-acetamido ketones from aldehydes and enolizable ketones in the presence of acetyl chloride and acetonitrile catalysed using sodium hydrogen sulfate under reflux at 85 ºC Entry Aldehyde Ketone Time Yield (%)a (m.p. ºC) Reported (h) Found [Ref ]b 1 C6H5CHO C6H5COCH3 2.5 83 103-105 102-104[25] 2 4-CH3C6H5CHO C6H5COCH3 3 82 112-114 112 [18] 3 3-NO2C6H5CHO C6H5COCH3 4.5 77 130-132 110-112[22] 4 4-NO2C6H5CHO C6H5COCH3 5 75 147-149 148-149[15] 5 4-ClC6H5CHO C6H5COCH3 4.5 81 147-149 147-148[25] 6 C6H5CHO 4-ClC6H5COCH3 3 78 112-114 115-117[25] 7 4-ClC6H5CHO 4-ClC6H5COCH3 3 80 142-144 141-143[12] 8 4-NO2C6H5CHO 4-ClC6H5COCH3 4.5 70 126-128 123-125[25] 9 C6H5CHO 4-CH3C6H5COCH3 3 86 120-122 119-121[25] 10 4-NO2C6H5CHO 4-CH3C6H5COCH3 5 72 67-70 liquid [13] 11 3-OHC6H5CHO C6H5COCH3 3.5 87 115-117 114-115[18] aYields refer to the pure isolated products. bRefer to the references of known products in the literature. In summary, we have demonstrated sodium hydrogen sulfate as a cheap, commercially available, reusable and non-corrosive catalyst for the synthesis of ß-acetamido ketones in ISSN 1551-7012 Page 136 ©ARKAT USA, Inc.