4-BroMo-2,3-dihydro-1H-indene

To a solution of 4-bromo-2, 3-dihydro-lH-inden-l-one (2 g, 10 mmol) in DCM (lOmL) was added TFA, then cooled to - 20°C. EtTo a solution of 4-bromoindan-1-one (200 mg, 947 umol) in dichloromethane (10 mL) was added a solution of trifluoromethanesulfonic acid (426 mg, 2.84 mmol) in dichloromethane (500 uL) and the reaction mixture was cooled to 0 °C. Then triethylsilane (220 mg, 1.90 mmol) in dichloromethane (500 uL) was added dropwise to the reaction mixture and the mixture was stirred at 0 °C for 0.5 hr. TLC detected most starting material remained. Then another batch of trifluoromethanesulfonic acid (426 mg, 2.84 mmol) and triethylsilane (220 mg, 1.90 mmol) was added in turn and the reaction mixture was stirred at 20 °C for 15.5 hrs. On completion, the reaction mixture was diluted with 15 mL DCM and washed with saturated sodium bicarbonate until pH = 7. The organic layer was dried over Na2SO4, filtered and concentrated in vacuo. The residue was purified by silica gel chromatography (petroleum ether) to give the title compound (1.00 g, 80percent yield) as colorless oil.Step 1 : 4-BromoindanTo a thick mixture of 4-aminoindan (2.66 g, 20 mmol) in 48percent tetrafluoroboric acid (20 ml) cooled in an ice bath was added a solution of sodium nitrite (1.6 g, 23 mmol) in water (20 ml) over 10 minutes. The mixture was stirred in ice for 10 minutes and was filtered and the filter cake was washed with cold 5percent tetrafluoroboric acid (10 ml) and then with cold water (10 ml). The filter cake was added in portions to copper (II) bromide (5.6 g, 25 mmol) in dimethyl sulfoxide (50 ml). The mixture was stirred for 30 minutes and was added to water (150ml). The mixture was extracted with ethyl acetate (150 ml) and the organic layer was washed with water. The organic layer was dried over magnesium sulfate and was filtered. The filtrate was concentrated and the residue was purified by flash chromatography on silica gel using heptane to give the title compound (0.6g, 15percent).

Molecular Weight:197.07
XLogP3:3.4
Exact Mass:195.98876
Monoisotopic Mass:195.98876
Heavy Atom Count:10
Complexity:122
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes