Lithium Hexamethyldisilazide → HCID 11638332, compound

Participants

Reaction Steps

To a pre-cooled (−78° C.) solution of 4,6-dichloro-2-(2-phenyl-propionyl amino)-benzoic acid methyl ester (0.82 g, 2.30 mmol) in dry THF (70 mL) was added dropwise LiHMDS [prepared by treatment of a hexamethyldisilazide (1.47 mL, 6.90 mmol) in dry THF (25 mL) with n-BuLi (3.70 mmol, 2.5M hexane solution) for 1 hour at −78° C.]. The reaction mixture was stirred for 1 hour and then refluxed overnight under a nitrogen atmosphere. After cooling to room temperature, the reaction was quenched by the addition of 1N HCl aqueous solution. Subsequently, the resultant was extracted with ethyl acetate (150 mL×3), and organic phase was washed with brine (150 mL×2) and water (150 mL×2) dried with magnesium sulfate. After evaporation the solvent, an objective compound (0.57 g, 78%) was obtained as yellow solid by a flash column chromatography (Hexane:EtOAc=4:1): 1H NMR (200 MHz, CD3OD+DMSO-d6) δ 1.61 (s, 3H, CH3), 6.96 (m, 1H, ArH), 7.08-7.34 (m, 6H, ArH); m.p. 222-225° C.; MS(EI) m/e 319 [M+], 285, 132, 104.

Provenance & Evidence