Toluene → N-(1-benzyl-7-bromo-3,4-dihydronaphthalen-2-yl)propionamide

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Reaction Steps

In a three-necked flask equipped with a Dean-Stark apparatus, heating mantle and magnetic stirrer were charged 1-benzyl-7-bromo-3,4-dihydronaphthalen-2(1H)-one (23.50 g, 74.6 mmol), propionamide (13.62 g, 186 mmol) and 4-methylbenzenesulfonic acid (1.284 g, 7.46 mmol) followed by toluene (200 ml). The resulting solution was heated to reflux overnight and monitored by HPLC (<6% starting material remained). The reaction mixture was cooled to r.t. and a suspension formed. To the mixture was added IPA and the resulting suspension was cooled to 0° C., stirred at 0° C. for 2 hours and filtered. The filtrate was concentrated and the residue was suspended in IPA/EtOH (50 ml/50 ml) at 0° C. for 1 hr and filtered to give additional product as a white solid. HPLC analysis indicated that both crops have similar purity. The solids were combined and further dried to give 22.5 g product as white solid.

Provenance & Evidence