反应详情

To a mixture of 28.8 g of (S)-3-methoxycarbonyl-2-oxopiperazine-1-acetic acid t butyl ester, 23.0 g of N-benzyloxycarbonyl-O-methyl-L-tyrosine and 202 ml of methylene chloride, 15.3 g of 1-(3-dimethylaminopropyl)-3-ehtylcarbodiimide was added. The mixture was stirred for 2 hours and concentrated under reduced pressure. The residue was disolved in ethyl acetate. The solution was washed with a 5% aqueous solution of potassium hydrogensulfate and a saturated sodium hydrogen carbonate. The organic layer was concentrated under reduced pressure to give 37.0 g of crude (S)-4-(N-benzyloxycarbonyl-O-methyl-L-tyrosyl)-3-methoxycarbonylmethyl-2-oxopiperazine-1-acetic acid t butyl ester. This product was dissolved in 74.0 ml of methylene chloride, to which was added 74.0 ml of trifluoroacetic acid. The mixture was stirred for one hour at room temperature. The reaction solution was concentrated under reduced pressure. The residue was subjected to azeotropy with toluene several times to afford 39.12 g of the title compound as a colorless oily product.

1. additionwas added
2. concentrationconcentrated under reduced pressure
3. washThe solution was washed with a 5% aqueous solution of potassium hydrogensulfate
4. concentrationThe organic layer was concentrated under reduced pressure