Lithium Hexamethyldisilazide → 1,1-Dimethylethyl N-[4-(3-amino-1,2,4-thiadiazol-5-yl)phenyl]carbamate

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Reaction Steps

To a solution of tert-butyl 4-(3-bromo-1,2,4-thiadiazol-5-yl)phenylcarbamate (3.22 g, 9.04 mmol) in THF (35 mL) at 0° C. was added LiHMDS (1 M in PhMe, 23 mL, 23.0 mmol). The reaction mixture was warmed to room temperature and stirred for 1.5 h. Water (20 mL) was added and the mixture was stirred at room temperature for 2 h. The reaction mixture was diluted with water, saturated NH4Cl, and EtOAc. The aqueous phase was extracted with EtOAc (2×), and the combined organic extracts were washed with brine (1×), dried over MgSO4, filtered, and concentrated. The concentrate was dissolved in 10% MeOH in DCM (200 mL), filtered through a pad of silica (2 cm), and diluted with hexanes (150 mL). The precipitate that formed was collected by filtration, washed with hexanes, and dried under high vacuum to give tert-butyl 4-(3-amino-1,2,4-thiadiazol-5-yl)phenylcarbamate.

Provenance & Evidence