Sodium Carbonate → 3-Benzyloxycarbonyl-1-ethoxycarbonyl-1'(3,4-dichlorobenzyl)-spiro[imidazolidine-4,3'-indoline]-2,2',5-trione

Participants

Reaction Steps

Ethyl chloroformate (0.6 g.) was added slowly to a stirred mixture of 3-benzyloxycarbonyl-1'-(3,4-dichlorobenzyl)-spiro[imidazolidine-4,3'-indoline]-2,2',5-trione (2.55 g.) and sodium carbonate (2.0 g.) in 1,2-dimethoxyethane (60 ml.). The mixture was stirred for 16 hours and the solid then removed by filtration. The filtrate was evaporated to give an oil which solidified on treatment with a few drops of ether. This solid was recrystallised from ethyl acetate/petrol 60-80 to give 3-benzyloxycarbonyl-1-ethoxycarbonyl-1'(3,4-dichlorobenzyl)-spiro[imidazolidine-4,3'-indoline]-2,2',5-trione (1.8 g.), m.p. 128°-131° C.

Provenance & Evidence