反应详情

A solution of ethyl chloroformate (0.55 g.) in 1,2-dimethoxyethane (20 ml.) was added dropwise to a stirred mixture of 1'-(3,4-dichlorobenzyl)-spiro[imidazolidine-4,3'-indoline]-2,2',5-trione (1.8 g.) and sodium carbonate (2.0 g.) in 1,2-dimethoxyethane (60 ml.). When the addition was completed, the mixture was stirred for 16 hours and then evaporated. The residual solid was dissolved in warm water (150 ml.) and the solution obtained was slowly acidified (concentrated hydrochloric acid). The solid which was precipitated was separated by filtration, washed with water, air-dried and recrystallised twice from propan-2-ol/petrol 60-80 to give 3-ethoxycarbonyl-1'-(3,4-dichlorobenzyl)-spiro[imidazolidine-4,3'-indoline]-2,2',5-trione (0.35 g.), m.p. 192°-194° C.

1. additionWhen the addition
2. customevaporated
3. dissolutionThe residual solid was dissolved in warm water (150 ml.)
4. customthe solution obtained
5. customThe solid which was precipitated
6. customwas separated by filtration
7. washwashed with water
8. customair-dried
9. customrecrystallised twice from propan-2-ol/petrol 60-80