A facile atom – economical synthesis of highly substituted pyrazolo- N -methyl-piperidine grafted spiro-indenoquinoxaline pyrrolidine heterocycles via a sequential multicomponent reaction

An expedient one-pot sequential five component synthesis of highly substituted pyrazolo-N-methyl-piperidine grafted spiro-indenoquinoxaline pyrrolidine heterocycles involving [3 + 2]-cycloaddition of azomethine ylides as the key step is described. The protocol provides a mild reaction condition, high yield of the products, high regioselectivity and operational simplicity to assemble complex structural entity in a single operation. The structure of the product was confirmed by spectroscopic techniques and elemental analysis.