反应详情

0.78 g of 2-morpholino-ethyl isocyanide was added at 22° to a suspension of 2.11 g of 1-[2(R)-[1(R)-carboxy-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl]-3-cyclopentylpropionyl)piperidine from Example 11 and 0.61 g of N-hydroxy-2-pyridone in 21 ml of methylene chloride and the mixture was stirred for 3 hrs. The solution was treated with 0.58 g of O-trimethylsilyl-hydroxylamine and stirred for 2 hrs. The reaction mixture was washed with saturated NaHCO3 solution and with water and evaporated. The residue was dissolved in 20 ml of t-butyl methyl ether and 0.23 ml of water, stirred for 11/2 hrs. at 22°, the suspension was diluted with 10 ml of hexane, filtered and the residue was dried at 22°/11 mbar, there being obtained 1.82 g (83%) of pure 1-[3-cyclopentyl-2(R)-[1(R)-(hydroxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)-ethyl]propionyl]piperidine I, MS (EI): 436 (40%).

1. stirringstirred for 2 hrs
2. washThe reaction mixture was washed with saturated NaHCO3 solution and with water
3. customevaporated
4. dissolutionThe residue was dissolved in 20 ml of t-butyl methyl ether
5. stirring0.23 ml of water, stirred for 11/2 hrs
6. additionat 22°, the suspension was diluted with 10 ml of hexane
7. filtrationfiltered
8. customthe residue was dried at 22°/11 mbar, there