The use of methanesulfonic acid as a Brønsted acid for direct ortho-acylation of phenols and naphthols proves to be a convenient, more general and direct route to various hydroxyaryl ketones. The route is regioselective, leading to ortho C-acylated products in satisfactory to high yields in most cases. The solvent free reactions described below exhibited environmentally […]
Methanesulfonic acid (MSA) was found to be an efficient catalyst for the synthesis of 1-substituted-1H-1,2,3,4-tetrazoles. A series of 1-substituted tetrazole compounds were synthesized from the reaction of various primary amines, sodium azide and triethyl orthoformate in the presence of catalytic amounts of MSA at room temperature. In this protocol, some of the tetrazole derivatives were […]
Efficient and one-pot synthesis of 1,8-dioxo-octahydroxanthenes was described by Knoevenagel condensation, Michael addition and cyclodehydration of dimedone. This reaction was carried out through condensation of dimedone and various aromatic aldehydes in the presence of task-specific Brønsted acidic ionic liquid under solvent free conditions. The catalyst could be recycled five times without significant loss of its […]
In this research, a green, operationally simple, highly efficient and facile cascade Biginelli reaction using various aromatic aldehydes, ethyl acetoacetate, and urea/thiourea has been developed. First, the ionic liquid was prepared from the reaction of 1-methyl-2-pyrolidone with methane sulfonic acid. Then, this ionic liquid was applied as an acidic catalyst in the synthesis of dihydropyrimidinones […]
