Sulfuric acid magnesium salt (1:1) → HCID 66972332, compound

Participants

Reaction Steps

Methyl 2(S)-amino-4-(pyridin-2-ylsulfanyl)butyrate (0.610 g, 2.33 mmol), 2,2,2,4′-tetrafluoroacetophenone (0.393 g, 2.05 mmol), and DIPEA (1.24 g, 9.63 mmol) were combined in CH2Cl2 (10 mL). TiCl4 (1.90 mmol in CH2Cl2) was added dropwise over a 5 min period. The resulting dark solution was stirred for 3 h at which time sodium cyanoborohydride (6.35 mmol) in methanol (5 mL) was added in one portion, and the brown solution stirred for an additional 45 min. The reaction mixture was diluted with ethyl acetate, poured onto a bed of MgSO4 and filtered. Concentration and purification by flash chromatography (50% ethyl acetate/hexanes) afforded 4-(pyridin-2-ylsulfanyl)-2(S)-[2,2,2-trifluoro-1-(4-fluorophenyl)ethylamino]-butyric acid methyl ester as a mixture of diastereomers.

Provenance & Evidence