反应详情

A mixture of the ester product from part (b) (2.4 g., 4.87 mmole), (±)-N-[3-(methylamino)-2-oxo-1-(phenylmethyl)propyl]benzamide (0.81 g., 2.43 mmole), prepared as set forth in Example 91(b), and diisopropylethylamine (0.85 ml., 4.87 mmole) in dimethylformamide (20 ml.) is stirred at room temperature overnight. The reaction mixture is poured into water (50 ml.), and extracted with ethyl acetate (3×100 ml.). The combined organic extracts are washed with saturated sodium bicarbonate, 10% potassium bisulfite, and water, dried (Na2SO4), and concentrated into a dark oily residue (2.8 g.). Flash chromatography (200 g. Merck silica gel, 10% ethyl acetate/methylene chloride, 20% methanol/ethyl acetate) affords 1.1 g. of (S)-7-[[[3-(benzoylamino-2-oxo-4-phenylbutyl]methylamino]acetyl]-1,4-dithia-7-azaspiro[4.4]nonane-8-carboxylic acid, diphenylmethyl ester as a yellow oil.

1. customprepared
2. extractionextracted with ethyl acetate (3×100 ml.)
3. washThe combined organic extracts are washed with saturated sodium bicarbonate, 10% potassium bisulfite, and water
4. dry with materialdried (Na2SO4)
5. concentrationconcentrated into a dark oily residue (2.8 g.)
6. customFlash chromatography (200 g. Merck silica gel, 10% ethyl acetate/methylene chloride, 20% methanol/ethyl acetate) affords 1.1 g