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Abstract: 2-Substituted benzothiazoles have been synthesized via one-pot reaction from aromatic aldehydes and o-aminothiophenol in the presence of FeCl3/Montmorillonite K-10 in absolute methanol at 25–30°C under ultrasound irradiation. The remarkable advantages are an inexpensive and easily available reagent, a simple procedure, mild conditions, short reaction times and moderate to good yields. [Copyright &y& Elsevier]

Synthesis of 2-aroyl-1,3,5-triaryl-4-carbethoxy-4-cyanocyclohexanols from chalcones with ethyl cyanoacetate is carried out in excellent yields with KF/basic alumina as catalyst under ultrasound irradiation. [Copyright &y& Elsevier]

The Michael reaction of chalcones as acceptors with various active methylene compounds such as diethyl malonate, nitromethane, cyclohexanone, ethyl acetoacetate and acetylacetone as donors catalyzed by KF/basic alumina results in adducts in high yield within a shorter time under ultrasound irradiation. [Copyright &y& Elsevier]

Synthesis of 2,3-disubstituted-2,3-dihydroquinazolin-4(1 H )-one derivatives catalyzed by dodecylbenzenesulfonic acid was carried out in 80–92% yields at 40–42 °C within 1–2 h in aqueous media via one-pot three-component condensation of isatoic anhydride, aromatic aldehyde and amine under ultrasound irradiation. Convenient work-up procedures, mild reaction conditions, avoiding the use of organic solvents, and friendly to environment are the salient features of this protocol. [ABSTRACT FROM AUTHOR]

Highlights: [•] A H2O2/NaI/(NH4)6Mo7O24 system was first reported for synthesis of 2-benzimidazole. [•] Ultrasound was demonstrated to be benefit for accelerating this reaction. [•] The amounts of oxidant and catalyst are markedly reduced while keeping good yields. [•] The reaction was performed efficiently in green conditions with high yields. [Copyright &y& Elsevier]

Abstract: 1,1-Disubstituted-2,6-diarylcyclohexane-4-ones have been synthesized via double Michael addition of 1,5-diaryl-1,4-pentadien-3-one with various active methylene compounds such as dimethyl malonate, diethyl malonate, methyl cyanoacetate and ethyl cyanoacetate catalyzed by KF/basic alumina under ultrasound irradiation to give good yields within a short time. [Copyright &y& Elsevier]

Abstract: One-pot synthesis of 3-aza-6,10-diaryl-2-oxa-spiro[4.5]decane-1,4,8-trione from 1,5-diaryl-1,4-pentadien-3-one can be carried out in good yields at 50°C under ultrasound irradiation. This method provided several advantages such as simple work-up procedure, shorter reaction time and higher yield. [Copyright &y& Elsevier]

Abstract: Synthesis of 2,2′-arylmethylene bis(3-hydroxy-5,5-dimethyl-2-cyclohexene-1-one) derivatives catalyzed by urea via the condensation of aromatic aldehydes and 5,5-dimethyl-1,3-cyclohexanedione was carried out in 80–98% yields at 50°C in aqueous media under ultrasound. This method provides several advantages such as environment friendliness, high yields and simple work-up procedure. [Copyright &y& Elsevier]