Hydrochloric Acid → HCID 20501037, compound

Participants

Reaction Steps

1'-(3,4-Dichlorobenzyl)-spiro[imidazolidine-4,3'-indoline]-2,2',5-trione (1.8 g.) was stirred in anhydrous N,N-dimethylformamide (50 ml.) under an atmosphere of nitrogen at 25° C. Sodium hydride (0.25 g; 50% w/v oil dispersion) was added, and the mixture stirred for 30 minutes. 3-Bromophthalide (1.15 g.) was then added. The mixture was stirred for 16 hours and then poured into water (150 ml.). The mixture was acidified (concentrated hydrochloric acid) and then extracted with ethyl acetate (150 ml.). The extract was washed with water (2×150 ml.), brine (150 ml.) and then dried (MgSO4). The dry solution was evaporated onto silica gel (10 g., Merck type 7734) which was then added to the top of a column of silica gel (150 g., Merck type 7734) made up in toluene. The column was eluted with an increasing concentration of ethyl acetate in toluene up to 25% v/v. The fractions containing the major product [Relative flow value: 0.5 on Merck SiO2TLC plates No. 5715; eluant: EtOAc/toluene, 1:1 v/v] were collected and evaporated to give an oil which crystallised on treatment with ethyl acetate/petrol 60-80 to give 1'-(3,4-dichlorobenzyl)-3-phthalidyl-spiro[imidazolidine-4,3'-indoline]-2,2',5-trione (0.4 g.), m.p. 154°-158° C.

Provenance & Evidence