Trifluoroacetic acid → 1-Benzyl-4-bromo-2,5-dimethoxybenzene

HRID 1486832Notes

Reaction equation

HRID 1486832 reaction equation
[Br:1][C:2]1[C:7]([O:8][CH3:9])=[CH:6][C:5]([C:10]([C:12]2[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=2)=O)=[C:4]([O:18][CH3:19])[CH:3]=1.FC(F)(F)C(O)=O.C([SiH](CC)CC)C.[NH4+].[Cl-]>C(Cl)Cl.O>[CH2:10]([C:5]1[CH:6]=[C:7]([O:8][CH3:9])[C:2]([Br:1])=[CH:3][C:4]=1[O:18][CH3:19])[C:12]1[CH:13]=[CH:14][CH:15]=[CH:16][CH:17]=1

Participants

7

Reactant 4

HCID 6422Trifluoroacetic acidHCID 12052TriethylsilaneHCID 25517Ammonium ChlorideHCID 67466544(4-Bromo-2,5-dimethoxyphenyl)(phenyl)methanone

Product 1

HCID 900142701-Benzyl-4-bromo-2,5-dimethoxybenzeneYield 98%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6344DichloromethaneSolvent2×

Procedure

To a solution of (4-bromo-2,5-dimethoxyphenyl)(phenyl)methanone (100 mg, 0.311 mmol) in 0.2 mL of anhydrous DCM (C=1.5M), were successively added dropwise trifluoroacetic acid (0.24 mL, 10 eq) and triethylsilane (0.2 mL, 4 eq). After 16 h of stirring at r.t., the reaction mixture was hydrolyzed with a saturated NH4Cl solution (5 mL). The layers were diluted with 20 mL of DCM and 20 mL of water and then separated. The aqueous layer was extracted twice with DCM (2×10 mL) The combined organic phase was washed twice with a saturated NaHCO3 solution (2×20 mL), brine (2×20 mL), dried over MgSO4, filtered and concentrated in vacuo. The product was obtained pure enough for further reaction in 98% yield (93.4 mg). 1H NMR (300 MHz, CDCl3) δ 7.34-7.25 (m, 2H), 7.24-7.17 (m, 3H), 7.08 (s, 1H), 6.69 (s, 1H), 3.95 (s, 2H), 3.78 (s, 3H), 3.78 (s, 3H); 13C NMR (75 MHz, CDCl3) δ 151.9 (C), 150.1 (C), 140.4 (C), 129.9 (C), 128.9 (CH), 128.5 (CH), 126.1 (CH), 116.1 (CH), 115.0 (CH), 109.1 (C), 57.0 (OCH3), 56.3 (OCH3), 35.9 (CH2Bn); MS (ESI) m/z: 324.5, 326.1 [M+NH4, 79Br, 81Br]+; 630.3, 632.0, 634.2 [2M+NH4, 79Br, 81Br]+.

Workup

  1. customseparated
  2. extractionThe aqueous layer was extracted twice with DCM (2×10 mL) The combined organic phase
  3. washwas washed twice with a saturated NaHCO3 solution (2×20 mL), brine (2×20 mL)
  4. dry with materialdried over MgSO4
  5. filtrationfiltered
  6. concentrationconcentrated in vacuo
  7. customThe product was obtained pure enough for further reaction in 98% yield (93.4 mg)

Sources & evidence

ORD record
ord-88ac974de66b4622ad2bda627e7d8eaf
Source dataset
uspto-grants-2016_08
Patent number
US09428500B2

Reaction notes

Loading…