6-BROMO-1,1,4,4-TETRAMETHYL-1,2,3,4-TETRAHYDRONAPHTHALENE

In a 50 mL round-bottomed flask was weighed T-2 (1.88 g, 10 mmol). Dry CH2CI2 (12 mL) was added and then the resulting solution was cooled to 0°C. Br2 (0.95 mL, 18.5 mmol, 1.8 equiv) was added dropwise. Then BF3*THF complex (1.2 mL, 11 mmol, 1.1 equiv) dissolved in 2 mL CH2CI2 was added dropwise. The mixture was stirred at room temperature under argon for 2 h, and then the reaction was quenched by the addition of water (10 mL). An organic layer was separated and an aqueous layer was extracted with CH2CI2 (2 x 20 mL). The organics were combined, dried with MgS0To a solution of tetrahydronaphthalene 22 (20.0 mmol)in MeOH (2.5 mL mmol-1), under nitrogen atmosphere, NBS(1.5 mmol) and TsOH (0.15 mmol) were added. The reactionmixture was refluxed at 55 °C for 48 h, then poured into saturated NaHCO3 solution and extracted with ethyl acetate(3 × 30 mL). The organic phase was dried over MgSO4 andthe solvent removed under vacuum. The product was purifiedby distillation at low pressure (0.5 mm Hg) at temperaturesbetween 90 and 145 °C. The product 23 was obtained ascolorless oil in 79percent yield. 1H NMR (300 MHz, CDCl3)37 δ 1.25 (s, 6H, 2CH3), 1.26 (s, 6H, 2CH3), 1.66 (s, 4H, 2CH2), 7.16 (d, 1H, J 8.5 Hz, Ar-H), 7.23 (dd, 1H, J 8.5, 2.1 Hz, Ar-H), 7.40 (d, 1H, J 2.1 Hz, Ar-H); 13C NMR (75 MHz, CDCl3) δ 31.72, 31.88, 34.06, 34.46, 34.83, 34.86, 119.40, 128.44, 128.65, 129.42, 143.82, 147.36.Aluminum chloride (700 mg, 5.25 mmol) was added slowly to a solution of 2, 5-dichloro-2, 5-dimethylhexane (11 g, 60 mmol) in bromobenzene (90 mL) at 0° C. Under a nitrogen purge of the reactor to 0 Set, and 2, 5-dichloro-2, 5-dimethyl-hexane (110 g, 600 mmol) and bromo benzene beamAluminum chloride (7 g, 52.5 mmol) in a mixture of (90mL) was added dropwise slowly. After stirring approximately 20 minutes, ether and hexane, 1: 1 into a solution of 1 L mixed in, wash with ice water, 10percent HCl, brine 100 mL, followed by removing under reduced pressure the organic layer and then removing water with magnesium sulfate and brown an oil is obtained. Was crystallized using methanol to give 6-bromo -1, 1, 4, 4- tetramethyl-1, 2, 3, 4-tetrahydronaphthalene 120 g (80percent yield).The crude 2, 5-dichloro-2, 5-dimethylhexane 13b (5.0 g, 27.30 mmol) was dissolved in 50 mL of methylene chloride on ice and bromobenzene (8.45 g, 53.80 mmol) , Aluminum chloride (728 g, 5.46 mmol) was added portionwise, stirred for 10 minutes, and allowed to spontaneously rise to room temperature with stirring for 0.5 hour. The reaction solution was poured into 100 mL of ice water, 50 mL of ethyl acetate was added and the mixture was extracted. The aqueous phase was extracted with ethyl acetate (50 mL of X3) and the organic phases were combined and washed successively with water (30 mL X 3) and saturated sodium chloride solution (30 mL X 3), dried over anhydrous sodium sulfate, filtered and the filtrate was concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography using eluent system B to give the title product 6-bromo-1, 1, 4, 4-tetramethyl-1, 2, 3, 4-tetrahydronaphthalene 13c (7.10 g, yellow liquid), yield: 97.4percent.

Molecular Weight:267.20
XLogP3:5.7
Exact Mass:266.06701
Monoisotopic Mass:266.06701
Heavy Atom Count:15
Complexity:242
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes