Bromine → Ethyl 2-(4-bromo-1-hydroxy-3-methylnaphthalen-2-yl)-2-tert-butoxyacetate

HRID 514159Notes

Reaction equation

HRID 514159 reaction equation
[C:1]([O:5][CH:6]([C:12]1[C:21]([CH3:22])=[CH:20][C:19]2[C:14](=[CH:15][CH:16]=[CH:17][CH:18]=2)[C:13]=1[OH:23])[C:7]([O:9][CH2:10][CH3:11])=[O:8])([CH3:4])([CH3:3])[CH3:2].C([O-])(O)=O.[Na+].[Br:29]Br.[O-]S([O-])(=S)=O.[Na+].[Na+]>C(Cl)(Cl)Cl.O>[Br:29][C:20]1[C:19]2[C:14](=[CH:15][CH:16]=[CH:17][CH:18]=2)[C:13]([OH:23])=[C:12]([CH:6]([O:5][C:1]([CH3:4])([CH3:2])[CH3:3])[C:7]([O:9][CH2:10][CH3:11])=[O:8])[C:21]=1[CH3:22]

Participants

7

Reactant 4

HCID 24408BromineHCID 24477Sodium ThiosulfateHCID 516892Sodium BicarbonateHCID 67126272Ethyl 2-tert-butoxy-2-(1-hydroxy-3-methylnaphthalen-2-yl)acetate

Product 1

HCID 67126338Ethyl 2-(4-bromo-1-hydroxy-3-methylnaphthalen-2-yl)-2-tert-butoxyacetateYield 97%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6212ChloroformSolvent2×

Procedure

A solution of ethyl 2-tert-butoxy-2-(1-hydroxy-3-methylnaphthalen-2-yl)acetate (1.24 g, 3.92 mmol) in CHCl3 (20 mL) was treated with solid NaHCO3 (843 mg, 9.80 mmol). Then a solution of Br2 (750 mg, 4.70 mmol) in CHCl3 (5.0 mL) was added dropwise over 2 min at 23° C. After 30 min, the reaction was treated with 10% Na2S2O3 solution (10 mL). After maximum decolorization was achieved, the reaction was diluted with H2O (10 mL) and extracted with DCM (3×10 mL). Combined organic phases were dried (Na2SO4), filtered, and concentrated. The residue was treated with DCM and wet-loaded onto a silica gel column and purified by flash chromatography (ethyl acetate/hexanes) giving the desired product (1.50 g, 97% yield). 1H NMR (400 MHz, CDCl3) δ 9.18 (s, 1H), 8.28 (d, J=8.6 Hz, 1H), 8.20 (d, J=8.6 Hz, 1H), 7.56 (dd, J=8.6, 8.6 Hz, 1H), 7.45 (dd, J=8.6, 8.6 Hz, 1H), 5.60 (s, 1H), 4.24-4.06 (m, 2H), 2.77 (s, 3H), 1.31 (s, 9H), 1.20 (t, J=7.0 Hz, 3H).

Workup

  1. extractionextracted with DCM (3×10 mL)
  2. dry with materialCombined organic phases were dried (Na2SO4)
  3. filtrationfiltered
  4. concentrationconcentrated
  5. additionThe residue was treated with DCM and wet-loaded onto a silica gel column
  6. custompurified by flash chromatography (ethyl acetate/hexanes)

Sources & evidence

ORD record
ord-a8b0fee006fc4242b76e059530058aff
Source dataset
uspto-grants-2015_08
Patent number
US09102614B2

Reaction notes

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