Lithium hydroxide, monohydrate → N,beta,beta-trimethyl-L-phenylalanyl-N1,3-dimethyl-N1-{(1S)-2-methyl-1-[(Z)-(3-methyl-2,5-dioxoimidazolidin-4-ylidene)methyl]propyl}-L-valinamide

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Reaction Steps

The yield, (3-methyl-2,5-dioxo-imidazolidin-4-yl)-phosphonic acid diethyl ester (0.915 g, 3.0 mmol) in ethanol (9 mL) is added to lithium hydroxide monohydrate (139 mg, 2.1 mmol) in 0.9 ml water to give a yellow solution. It is then added to N-{1-[(1-formyl-2-methyl-propyl)-methyl-carbamoyl]-2,2-dimethyl-propyl}-3-methyl-2-methylamino-3-phenyl-butyramide (˜1 mmol, from Reference Example 12) in 3 mL ethanol. The reaction mixture is stirred at room temperature for 60 hours. Solvent is evaporated. The residue is diluted with dichloromethane/water. The aqueous layer is extracted twice with dichloromethane. The combined organic extracts are washed with brine, dried oversodium sulfate, filtered and concentrated in vacuo. The residue is chromatographed by reverse phase HPLC (0.01% trifluoroacetic acid in water/acetonitrile) to give the product as a white solid, N,beta,beta-trimethyl-L-phenylalanyl-N1,3-dimethyl-N1-{(1S)-2-methyl-1-[(Z)-(3-methyl-2,5-dioxoimidazolidin-4-ylidene)methyl]propyl}-L-valinamide: 25 mg (4%) MS (ES+): (M+H)=514.3

Provenance & Evidence