反应详情

A mixture of Nα -[N-t-butoxycarbonyl-3-(2-pyridyl)-D-alanyl]-1,β-dimethyl-D-tryptophan methyl ester (10.54 g) and trifluoroacetic acid (80 ml) was stirred on an ice bath for 30 minutes. After removal of the solvent, resultant crude residue was dissolved in ethanol (150 ml) and saturated ammonia in ethanol (150 ml) was added to the solution and resultant mixture was stirred for 16 hours at ambient temperature. After evaporation of the solvent, chloroform (200 ml) was added to the mixture. The insoluble material was filtered off and again solvent was evaporated in vacuo to give an oil which was chromatographed on silica gel (250 g, chloroform-methanol 20:1 as eluent) to afford (3R,6R)-3-[(R)-1-(1-methylindol-3-yl)ethyl]-6-(2-pyridylmethyl)piperazine-2,5-dione.

1. customAfter removal of the solvent, resultant crude residue
2. dissolutionwas dissolved in ethanol (150 ml)
3. additionsaturated ammonia in ethanol (150 ml) was added to the solution and resultant mixture
4. stirringwas stirred for 16 hours at ambient temperature
5. customAfter evaporation of the solvent, chloroform (200 ml)
6. additionwas added to the mixture
7. filtrationThe insoluble material was filtered off
8. customagain solvent was evaporated in vacuo
9. customto give an oil which
10. customwas chromatographed on silica gel (250 g, chloroform-methanol 20:1 as eluent)