1-Bromobenzocyclobutene

Colorless to pale yellow liquid

In a 250 mL round bottomed flask equipped with a drying tube and a condenser, a solution of cycloheptatriene (30.7 g, 300 mmol), bromoform (25.3 g, 100 mmol), anhydrous K2COGeneral procedure: In a 250 ml three necked round bottom flask equipped with a polytetraflouroethylene (Teflon polymer, Dupont, Wilmington, Del.) coated magnetic stir bar, potassium hydroxide (1.38 g, 1 eq) was dissolved in water (6.83 g). Then 4-acetoxy styrene (4 g, 1 eq) was added dropwise at room temperature, and the solution turned from colorless to pale orange. Potassium carbonate (6.82 g, 2 eq) was added portionwise, and the solution was stirred for one hour. The flask was equipped with a reflux condenser, then In a 250 ml rbf with magnetic stir bar was added aminophenol (1 g, 1 eq), THF (15 ml) and KOtBu (1.23 g, 1.2 eq). The mixture was allowed to stir for 1 hour at room temperature. Bromo BCB (1.68 g, 1 eq) was added in THF (15 ml). The reaction was capped and allowed to stir for 12 h at room temperature. Water (100 ml) was then added. Ethyl acetate (3×100 ml) was used to extract the product from the aqueous phase. The combined organics were dried over sodium sulfate, filtered and concentrated in vacuo. The crude residue was subjected to a column of silica gel using heptanes and ethyl acetate (9:1) as eluent to give product (892 mg, 46%) as a dark oil. (0077) 1H NMR (500 MHz, Chloroform-d) delta 7.32 (dt, J=6.6, 4.3 Hz, 1H), 7.28-7.23 (m, 2H), 7.18 (d, J=7.4 Hz, 1H), 6.86 (d, J=9.0 Hz, 2H), 6.69 (d, J=9.0 Hz, 2H), 5.59 (dd, J=4.3, 2.1 Hz, 1H), 3.66 (dd, J=14.1, 4.3 Hz, 1H), 3.46 (br s, 2H), 3.28 (d, J=14.1 Hz, 1H). 13C NMR (126 MHz, Chloroform-d) delta 151.04, 145.18, 142.64, 140.49, 129.73, 127.29, 123.47, 123.00, 116.48, 116.36, 74.89, 39.47. DSC Showed an exotherm peak temperature at 179 C at a scan rate of 10 C/min.Magnesium turnings (210 mg), sodium hydride (29 mg, 60% oil dispersion) and a magnetic stir bar were added to a 100 ml rbf, capped with a rubber septum and placed under vacuum and allowed to stir for 4 hours. A solution of BrBCB (750 mg) in THF (20 ml) was added via syringe slowly. The solution turned bright yellow and was placed under a nitrogen atmosphere. The solution was left to stir for 30 minutes then added via syringe to a 100 ml rbf containing a stir bar, bromostyrene (1 g), Pd PEPPSI-iPr (1, 3-Bis(2, 6-Diisopropylphenyl)imidazol-2-ylidene)(3-chloropyridyl)palladium(II) dichloride, CAS no: 905459-27-0) catalyst (190 mg, 5 mol %) and THF (15 ml ) under nitrogen and capped with a rubber septum. The mixture turned black after about 30 minutes and was left to stir at room temperature for 12 h. The mixture was added to a separatory funnel containing water (100 ml), and extracted with ethyl acetate (3×100 ml). The combined organics were dried with brine (100 ml) and sodium sulfate, filtered and concentrated in vacuo. The residue was recrystallized in methanol to give the desired product as a colorless solid (203 mg, 18% yield). 1H NMR (500 MHz, Chloroform-d) delta 7.49 (d, J=8.1 Hz, 2H), 7.44-7.26 (m, 6H), 6.84 (dd, J=17.7, 10.8 Hz, 1H), 5.86 (d, J=17.7 Hz, 1H), 5.35 (d, J=10.8 Hz, 1H), 4.86-4.75 (m, 1H), 3.85 (dd, J=13.9, 5.7 Hz, 1H), 3.22 (dd, J=13.9, 2.7 Hz, 1H). A DSC of the resulting monomer showed an exotherm (cure) peak max of 165 C. at a scan rate of 10 C./min. (0070) The yield in the above reaction was very low. Further, no ether linkage resulted from the reaction. However, the cure temperature of the monomer was acceptable.In a 250 ml three necked round bottom flask equipped with a polytetraflouroethylene (Teflon polymer, Dupont, Wilmington, Del.) coated magnetic stir bar, potassium hydroxide (1.38 g, 1 eq) was dissolved in water (6.83 g). Then 4-acetoxy styrene (4 g, 1 eq) was added dropwise at room temperature, and the solution turned from colorless to pale orange. Potassium carbonate (6.82 g, 2 eq) was added portionwise, and the solution was stirred for one hour. The flask was equipped with a reflux condenser, then 7-bromobicyclo[4.2.0]octa- 1 , 3, 5-triene (10.0 g, 54.6 mmol) and ethylene glycol (100 mE) were added to a250 mE round-bottom flask. The biphasic mixture wascooled to 0 C. followed by the slow addition of solid silver(I) tetrafluoroborate (11.7 g, 60.1 mmol) to maintain a temperature of about 30 C. After addition, the reaction mixture was stirred at 50 C. for 3 hrs. Once cooled down to room temperature, 200 ml water and 400 ml ether were added. The resulting mixture was filtered through celite. The organic layer was washed three times with each 300 ml water and then dried over Na2504 and concentrated to give an oil. The oil was purified by column chromatography on silica gel using 5% ethyl acetate in hexanes (4.66 g). The product had the following characteristics: 'H-NMR (400 MHz, CDC13): oe 7.36-7.27 (m, 1H), 7.27-7.20 (m, 2H), 7.15 (dp, J=7.2, 1.0 Hz, 1H), 5.20-5.03 (m, 1H), 3.90-3.61 (m, 4H), 3.56-3.39 (m, 1H), 3.21- (m, 1H), 2.23-1.98 (br s, 1H). '3C-NMR (101 MHz, CDC13): oe 145.64, 142.42, 129.49, 127.10, 123.54, 122.70, 76.96, 69.75, 61.91, 38.53

Molecular Weight:183.04
XLogP3:2.1
Exact Mass:181.97311
Monoisotopic Mass:181.97311
Heavy Atom Count:9
Complexity:111
Undefined Atom Stereocenter Count:1
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes