反应详情

A solution of benzyl chloroformate (7.6 g.) in 1,2 dimethoxyethane (50 ml.) was added dropwise to a stirred mixture of 1'-(3,4-dichlorobenzyl)-spiro[imidazolidine-4,3'-indoline]-2,2',5-trione (7.4 g.) and sodium carbonate (8 g.) in 1,2 dimethoxyethane (200 ml.). When the addition was completed the mixture was stirred for 72 hours and then evaporated. The residual solid was dissolved in warm water (300 ml.) and the solution obtained was carefully acidified (concentrated hydrochloric acid) and then extracted with ethyl acetate (3×150 ml.). The combined extracts were washed successively with water (2×200 ml.) and brine (1×200 ml.) and then dried (MgSO4). Evaporation of the solvent gave a buff solid which was recrystallised from ethyl acetate/petrol 60-80 to give 3-benzyloxycarbonyl-1'-(3,4-dichlorobenzyl)-spiro[imidazolidine-4,3'-indoline]-2,2',5-trione (6.5 g.), m.p. 215°-217° C.

1. additionWhen the addition
2. customevaporated
3. dissolutionThe residual solid was dissolved in warm water (300 ml.)
4. customthe solution obtained
5. extractionextracted with ethyl acetate (3×150 ml.)
6. washThe combined extracts were washed successively with water (2×200 ml.) and brine (1×200 ml.)
7. dry with materialdried (MgSO4)
8. customEvaporation of the solvent
9. customgave a buff solid which
10. customwas recrystallised from ethyl acetate/petrol 60-80