Chloroacetyl chloride → 2-Chloro-N-(1-oxo-1,2,3,4-tetrahydronaphthalen-2-yl)acetamide

Chloroacetyl chloride (14 g, 124 mmol) was added to a solution of 2-amino-3,4-dihydro-2H-naphthalen-1-one hydrochloride (16 g, 81 mmol) and triethylamine (41 g, 405 mmol) in tetrahydrofuran (600 ml) and the mixture was stirred for one hour. The solution was partitioned between water and ethyl acetate. The organic layer was washed with brine, dried over magnesium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (eluent; 5-10% methanol in chloroform) to afford 2-chloro-N-(1-oxo-1,2,3,4-tetrahydronaphthalen-2-yl)-acetamide (7.58 g, 31.9 mmol, 39%) as white crystals.