Ethylene Glycol → 2-(3-Bromophenyl)-2-methyl-1,3-dioxolane
Reaction equation
N#N.[Br:3][C:4]1[CH:5]=[C:6]([C:10](=[O:12])[CH3:11])[CH:7]=[CH:8][CH:9]=1.COC(OC)OC.[CH2:20](O)[CH2:21][OH:22]>>[Br:3][C:4]1[CH:5]=[C:6]([C:10]2([CH3:11])[O:22][CH2:21][CH2:20][O:12]2)[CH:7]=[CH:8][CH:9]=1Participants
Conditions
- Temperature
- 95 °C
Procedure
In a flame dried round-bottomed flask equipped with a magnetic stir bar and under inert atmosphere (N2), a solution of 3′-bromoacetophenone (4.67 mL, 33.89 mmol) in ethylene glycol (36.4 mL) was treated with trimethylorthoformate (7.58 mL, 69.14 mmol) followed by LiBF4 (648 mg, 6.78 mmol). The reaction mixture was heated at 95° C. for 3.5 h. The reaction mixture was cooled to rt and partitioned between ether (100 mL) and sat. aq. Na2CO3 (25 mL). The layers were separated and the aq. layer extracted twice with ether (50 mL). The combined org. extracts were dried over Na2SO4, filtered, and the solvent was removed under reduced pressure. Purification of the residue by FC (9:1 hept-EA) gave the title compound as a dark yellow oil. TLC: rf (9:1 hept-EA)=0.44. LC-MS-conditions 02: tR=1.00 min.
Workup
- temperatureThe reaction mixture was cooled to rt
- custompartitioned between ether (100 mL) and sat. aq. Na2CO3 (25 mL)
- customThe layers were separated
- extractionthe aq. layer extracted twice with ether (50 mL)
- dry with materialextracts were dried over Na2SO4
- filtrationfiltered
- customthe solvent was removed under reduced pressure
- customPurification of the residue by FC (9:1 hept-EA)
Sources & evidence
- ORD record
- ord-74d6f94912b9441980cb8207ddc13e0f
- Source dataset
- uspto-grants-2014_03
- Patent number
- US08674111B2
Reaction notes
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