Water → 8-Bromo-2,3,4,5-tetrahydrobenzo[b]oxepine
Reaction equation
Br[C:2]1[CH:7]=[CH:6][C:5]([Br:8])=[CH:4][C:3]=1[O:9][CH2:10][CH2:11][CH2:12][CH2:13]Br.C([Li])CCC.O>O1CCCC1.CCCCCC>[Br:8][C:5]1[CH:6]=[CH:7][C:2]2[CH2:13][CH2:12][CH2:11][CH2:10][O:9][C:3]=2[CH:4]=1Participants
Procedure
To a solution of 12.7 g (33 mmol) of 1,4-dibromo-2-(4-bromobutoxy)benzene in 220 mL of anhydrous tetrahydrofuran and 55 mL of hexane under nitrogen cooled in a dry ice/acetone bath was added dropwise 14.5 mL (36.3 mmol, 1.1 equiv) of 2.5M n-butyllithium in tetrahydrofuran, keeping the internal temperature <−70° C. The mixture was stirred with cooling for 30 minutes, then at ambient temperature. After 5 hours, 220 mL of water was added and the layers were separated. The aqueous layer was extracted with 2×160 mL of ether. The combined organic layer was dried over sodium sulfate, filtered, and concentrated under reduced pressure to give 7.7 g of a yellow oil. Purification by flash chromatography (5-20% ethyl acetate in hexanes) gave the product as a yellow oil. MS (m+1)=228.1; 1H NMR (400 MHz, CDCl3) 7.15 (d, 1H, J 2 Hz), 7.09 (m, 1H), 6.99 (d, 1H, J 8 Hz), 4.01 (m, 2H), 2.76 (m, 2H), 1.96 (m, 2H), 1.71 (m, 2H).
Workup
- customthe internal temperature <−70° C
- temperaturewith cooling for 30 minutes
- customat ambient temperature
- customthe layers were separated
- extractionThe aqueous layer was extracted with 2×160 mL of ether
- dry with materialThe combined organic layer was dried over sodium sulfate
- filtrationfiltered
- concentrationconcentrated under reduced pressure
Sources & evidence
- ORD record
- ord-46de254db1f74e96ac9975a49bd80b02
- Source dataset
- uspto-grants-2010_12
- Patent number
- US07855201B2
Reaction notes
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