An Investigation Into A Microwave-Enhanced Solvent-Free Mannich Condensation Reaction

Microwave irradiation has gained in popularity in recent years since it has been found to accelerate various chemical reactions. Microwaves are generally considered to be more environmentally friendly than traditional methods for activating chemical reactions. An investigation into a microwave-enhanced, solventless Mannich condensation was performed. The efficiency of a standard household microwave was compared to that of an industrial microwave, with the industrial microwave proving to be more effective. The advantages of using microwave irradiation for a Mannich condensation include milder reaction conditions, the absence of solvent, less waste, and shorter reaction times. The reaction between terminal alkynes, secondary amines, and paraformaldehyde on Culdoped alumina, to yield β-aminoalkynes, was investigated. Cuprous iodide and alumina were both required for successful reactions. The microwave reactions produced good yields of the β-aminoalkynes.