反应详情

To 1.96 g (7.5 mmol) of the above ester in 15 ml of methanol and 15 ml of tetrahydrofuran was added 10 ml of 1N aqueous sodium hydroxide. After 30 minutes, 4 ml of 10% aqueous hydrochloric acid was added. The organic solvents were evaporated and the resultant crystalline product was filtered and washed with cold ethanol and then ether. This material was dissolved in 20 ml of tetrahydrofuran and 4 ml of dimethylformamide. Dicyclohexylcarbonyldiimidazole (1.3 g, 2.2 eq) was added and the reaction allowed to stir for 15 minutes. Cysteine ethyl ester hydrochloride (1.6 g, 2.5 eq) and triethylamine (1.2 ml) were then added. After a further three hours, the reaction was diluted with ethyl ether containing 5% methylene chloride and washed once with 10% aqueous hydrochloric acid and twice with brine. After drying with magnesium sulfate and evaporating the solvents, the crude product was crystallized by dissolving in chloroform containing a minimal amount of ethanol and then adding an excess of ether. The crystals were filtered and dried to give pure N-[[(4-methyl-coumarin-7-yl)amino]acetyl]cysteine ethyl ester.

1. customThe organic solvents were evaporated
2. filtrationthe resultant crystalline product was filtered
3. washwashed with cold ethanol
4. dissolutionThis material was dissolved in 20 ml of tetrahydrofuran
5. waitAfter a further three hours
6. washwashed once with 10% aqueous hydrochloric acid and twice with brine
7. dry with materialAfter drying with magnesium sulfate
8. customevaporating the solvents
9. customthe crude product was crystallized
10. dissolutionby dissolving in chloroform containing a minimal amount of ethanol
11. additionadding an excess of ether
12. filtrationThe crystals were filtered
13. customdried