Benzyl chloroformate → 4-(Benzyloxycarbonylamino)thiochromane-7-carboxylic acid methyl ester

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Reaction Steps

To an ethyl acetate (200 ml) solution of 4-aminothiochromane-7-carboxylic acid methyl ester (8.00 g) was added saturated aqueous sodium hydrogencarbonate solution (200 ml), and benzyloxycarbonyl chloride (6.75 g) was added at room temperature. The mixture was stirred at the same temperature for 2 hrs. The reaction mixture was extracted with ethyl acetate, washed with water, saturated aqueous sodium hydrogencarbonate solution and saturated brine, and dried over anhydrous magnesium sulfate. The solvent was concentrated under reduced pressure and the obtained residue was purified by silica gel column chromatography to give the objective 4-(benzyloxycarbonylamino)thiochromane-7-carboxylic acid methyl ester (12.8 g) as colorless crystals.

Provenance & Evidence