Search

Amberlyst-15 has been identified as a green and reusable catalyst in the synthesis of spiro 2,3-dihydroquinazolin-4(1H)-ones under ultrasound irradiation at room temperature. The reaction can be performed in an open flask as the conversion was found to be not sensitive to the presence of air or atmospheric moisture. The methodology was found to be general and a wide variety of spiro 2,3-dihydroquinazolin-4(1H)-ones were prepared from 2-aminobenzamides and cyclic ketones within a few minutes in quantitative yields. The products isolated do not require any chromatographic purification. This method provides advantages such as shorter reaction time, high yields of products, and simple operational procedures. Some of the compounds showed chorismate mutase inhibitory properties when tested in vitro.

AlCl3 facilitated C–N bond forming reaction between 2,3-dichloroquinoxaline and anilines affording a convenient method for the preparation of N-aryl substituted 3-chloroquinoxalin-2-amines. A related N-benzyl derivative, however, was prepared via a conventional method. These N-alkyl/aryl substituted 3-chloroquinoxalin-2-amines on coupling with terminal alkynes in toluene under Pd/C–Cu catalysis afforded a range of 1,2-disubstituted pyrrolo[2,3-b]quinoxalines within 3–5 h in good to excellent yields. Some of the compounds synthesized showed promising anti-proliferative properties when tested in vitro against two cancer cell lines. Docking studies indicated that these molecules interact well with human Akt in silico.

AgNO 3 facilitated the intramolecular ring closure of o -(1-alkynyl)benzenesulfonamides via a regioselective C–N bond forming reaction leading to the formation of 3-substituted benzothiazine derivatives. A number of compounds were prepared in good yields by using this inexpensive and safe methodology. All the compounds synthesized were evaluated for their cyclooxygenase (COX) inhibiting properties in vitro. A number of compounds that do not contain an enolic hydroxyl group showed selectivities toward COX-2 over COX-1 inhibition. This was further supported by the predictive binding mode of two compounds with COX-1 and -2 proteins through molecular docking studies.

The design and synthesis of 4-alkynyl pyrazole derivatives has led to the identification of new class of PDE4 inhibitors. All these compounds were accessed for the first time via a facile Pd/C-CuI-PPh(3) mediated C-C bond forming reaction between an appropriate pyrazole iodide and various terminal alkynes. In vitro PDE4B inhibitory properties and molecular modeling studies of some of the compounds synthesized indicated that 4-alkynyl pyrazole could be a promising template for the discovery of novel PDE4 inhibitors.