The present invention provides an improved processes having practical utility for preparing 2-oxindoles of formula I comprising preparation of 2-nitroarylmalonate diester of formula II as first intermediate and subsequent insitu reductive cyclisation using metal acid combination and its modified work-up to form compound of formula I free from metal generated impurity of formula M(OH)X wherein M is metal cation and X is anion. R is selected from hydrogen, linear, branched or cyclic alky!, aryl. substituted aryl. heteroaryl. haloalkyl like CFj, alkoxy. haloalkoxy. thioalkyl and halogen preferably chloro Formula I u herein R and R" are same or different and is selected from linear.branehed and cyclic alky! (C1-C4groLips)preferably methyl R is selected from hydrogen, linear, branched or cyclic alkyl. aryl. substituted aryl. heteroaryl. haloalkyl like CF3 . alkoxy. haloalkoxy. thioalkyl and halogen preferably chloro Formula II
