Indeed, it is a sequential multicomponent reaction, which is performed in a sealed tube. First, carbodiimide (1.1equiv.) and malonic acid ester (1equiv.) are mixed together at RT overnight in acetonitrile (0.1M), and then K2CO3 (2.1equiv.) and alkyl halide (4equiv.) were added and heated at 120°C for 30min. I think I will do this step in the microwave oven....for 5min.....
The yields obtained with this type of reaction are between 52 and 90%, which is good, but there is still drawbacks first of all the R1 must be introduced before the MCR, second, depending on the substituents needed the carbodiimides have also to be synthesized before, and third we have a racemic mixture....
