2,3-Dihydroxybutanedioic Acid → 4-[5-(4-Fluorophenyl)-1-(4-fluorophenylamino)-5-hydroxy-2-(2-oxo-4-phenyloxazolidine-3-carbonyl)-pentyl]-benzonitrile

Participants

Reaction Conditions

Reaction Steps

Under argon, 2.5 g of 3-[5-(4-fluorophenyl)-5-hydroxypentanoyl]-4-phenyloxazolidin-2-one were dissolved in 30 ml of dichloromethane. 3.9 g of 4-[(4-fluorophenylimino)-methyl]-benzonitrile were added and the mixture was cooled to −10° C. 6.4 ml of diisopropylethylamine and, over a period of 30 min, 4.05 ml of trimethylsilyl chloride were added to this mixture so that the temperature did not exceed −5° C. The mixture was stirred at this temperature for 1 additional hour and then cooled to −25° C. 0.8 ml of titanium tetrachloride were then added slowly. The dark mixture was stirred at a temperature ranging from −25 to −30° C. overnight and then decomposed using 35 ml of a 7 percent strength solution of tartaric acid and then stirred at room temperature for another hour. 15 ml of a 20 percent strength solution of sodium bicarbonate were then added, and the mixture was again stirred for 1 hour. Following magnesium sulfate and concentrated to about 10 ml. Following the addition of 2 ml of bistrimethylsilylacetamide, the mixture was heated at reflux for 30 min and then concentrated under reduced pressure. The residue was crystallized using ethyl acetate/heptane. The product was filtered off with suction and dried under reduced pressure. This gave the product of molecular weight 653.81 (C37H37F2N3O4Si); MS (ESI+): 654.3 (M+H+), 582.2 (M+H+—Si(CH3)3).

Provenance & Evidence