Synthesis of 2([Methyl-5-[(E)-2-aryl-1-ethenyl]-4-isoxazolyl]imino)-1,3-thiazolan-4-ones and Their Mannich Bases

SO2F2-Mediated N-Alkylation of Imino-Thiazolidinones

“…18,19 The last method is a Mannich-type reaction between formaldehyde and secondary amines which allowed formation of the N-en isomer of the dialkylaminomethylated product with moderate to excellent yields (d). 20 A major obstacle reported in the literature on alkylation of free NH imino-thiazolidinone is the lack of diversity on the newly introduced alkyl chain. Knowing that there is a strong demand for a handy late-stage introduction of alkyl groups on this type of scaffold, we decided to turn our attention to the development of a method that would be simple, economical, and versatile.…”

“…Though, a dimethylaminomethylene group will thus be introduced on position 5 of imino-thiazolidinone. , On the other hand, methylation with dimethyl sulfate can be regioselective depending on the reaction conditions. Indeed, a reaction carried out under reflux of acetone favored endocyclic N -methylation while the one at low temperature in EtOH favored exocyclic N -methylation (Scheme c). , The last method is a Mannich-type reaction between formaldehyde and secondary amines which allowed formation of the N -en isomer of the dialkylaminomethylated product with moderate to excellent yields (Scheme d) . A major obstacle reported in the literature on alkylation of free NH imino-thiazolidinone is the lack of diversity on the newly introduced alkyl chain.…”

A Fast and Highly Efficient Protocol for Synthesis of Pyrrolo[2,3-d]isoxazoles and a New Series of Novel Benzyl Bis-pyrrolo[2,3-d]isoxazoles Using Task-Specific Ionic Liquids as Catalyst and Green Solvent

“…[10][11][12] Similarly, 1-methyl imidazolium tetrafluoroborates has been exploited as an efficient Bronsted acid promoter ionic liquid in various organic transformations. [13][14][15] As a part of our study on environmentally friendly organic synthesis with isoxazoles, [16][17][18][19] avoiding organic solvent and toxic catalyst in reactions, we demonstrated the use of room temperature ionic liquids as efficient catalysts as well as reaction media for Knoevenagel and Michael reactions and also for conducting reductive cyclization.Looking for a valuable procedure for the conversion of nitro styrylisoxazoles (3) to pyrrolo[2,3-d]isoxazoles (4), several approaches have been investigated. One method for pyrrole ring formation is by de-oxygenative cyclization of nitro styryl compounds using triethyl phosphite (TEP).…”