Pivaloyl chloride → Methyl 2-amino-3-[2-(tert-butyldimethylsilanyloxymethyl)furan-3-yl]-6-(2,2-dimethylpropionylamino)benzoate

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Reaction Steps

Pivaloyl chloride (0.353 g) was added to a stirred, cooled mixture of methyl 2,6-diamino-3-[2-(tert-butyldimethylsilanyloxymethyl)furan-3-yl]benzoate (Intermediate 36, 1.0 g) and sodium bicarbonate (0.268 g) in ethyl acetate (20 mL) and water (7 mL) at 0° C. The mixture was allowed to warm to room temperature and stirred for 1.5 hours. Further pivaloyl chloride (0.048 g) was added and the mixture was stirred for 1 hour. Ethyl acetate was added and the layers were separated. The organic layer was washed with aqueous sodium bicarbonate solution dried (MgSO4) and filtered. The filtrate was evaporated to dryness and the residue was purified by chromatography on silica eluting with a mixture of ethyl acetate and cyclohexane with a gradient of 5-20% to give methyl 2-amino-3-[2-(tert-butyldimethylsilanyloxymethyl)furan-3-yl]-6-(2,2-dimethylpropionylamino)benzoate (0.744 g) as an oil.

Provenance & Evidence