Diethylenetriamine supported on cellulose as a biodegradable and recyclable basic heterogeneous catalyst for the synthesis of spirooxindole derivatives

In the present study, the synthesis of diethylene triamine supported on cellulose biopolymer as a biodegradable solid basic heterogeneous catalyst was suggested. Then, the applicability of the synthesized catalyst cellulose bonded N-propyl diethylene triamine (CBPDETA) was tested for the synthesis of oxindole derivatives, an important class of potentially bioactive compounds. A various series of tetrahydrospiro-[chromene-indoline]-carbonitrile and dihydro-spiro[pyrano quinoline--indoline]-carbonitrile are obtained in water, an excellent solvent in terms of environmental impact, in high yield (78- 98%) from one-pot reaction procedure involving dicarbonyl/ 4-hydroxycoumarine , malononitrile and isatin compounds. The catalyst has been reused several times, without observable loss of activity and selectivity.