Carbon Disulfide → 4-Bromo-2-i-butyl-1-indanone

A 500-ml four-necked round flask equipped with a stirrer, a Dimroth condenser, a dropping funnel, a thermometer and a NaOH trap was charged with 20.33 g (152.5 mmol) of anhydrous aluminum chloride and 70 ml of carbon disulfide. To the mixture was added dropwise a solution containing 40.2 g (132.6 mmol) of the above-obtained 3-(2-bromophenyl)-2-1-butylpropionic acid chloride dissolved in 50 ml of carbon disulfide under a nitrogen atmosphere while cooling with ice bath. After the addition was completed, the temperature in the flask was elevated to room temperature, and the mixture was stirred for 1 hour. Then, the reaction mixture was quenched by pouring onto 200 ml of ice water, which was then extracted with 100 ml of ether three times. The combined organic phase was washed with 100 ml of a saturated aqueous solution of sodium bicarbonate, and then 100 ml of a saturated NaCl aq., followed by dried over anhydrous Na2SO4. The solvent was evaporated under reduced pressure to give 37.4 g of the desired produce as an orange liquid. This ketone was used in the next reaction without further purification.