3-Methylbenzo[b]thiophene → 2-Fluoro-3-methyl-1-benzothiophene

HRID 10229

Reaction equation

HRID 10229 reaction equation
[CH3:1][C:2]1[C:6]2[CH:7]=[CH:8][CH:9]=[CH:10][C:5]=2[S:4][CH:3]=1.[B-](F)(F)(F)[F:12].[B-](F)(F)(F)F.C1[N+]2(CCl)CC[N+](F)(CC2)C1>C(#N)C>[F:12][C:3]1[S:4][C:5]2[CH:10]=[CH:9][CH:8]=[CH:7][C:6]=2[C:2]=1[CH3:1]

Participants

4

Reactant 2

HCID 738173-Methylbenzo[b]thiopheneHCID 2724933Selectfluor

Product 1

HCID 219783712-Fluoro-3-methyl-1-benzothiopheneYield 72%

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent

Conditions

Temperature
70 °C

Procedure

A stirred solution of 3-methylbenzothiophene (0.51 g, 3.37 mmol) in acetonitrile (5 μL) under nitrogen was treated with SELECTFLUOR™ (1.25 g, 3.35 mmol) and heated to 70° C. overnight. The solvent was removed in vacuo. The residue was taken up in ethyl acetate and washed with sodium hydrogen carbonate solution, water and brine, dried over MgSO4 and evaporated in vacuo. Purification by flash column chromatography on silica, eluting with isohexane, gave 2-fluoro-3-methyl-1-benzothiophene (72% pure, 190 mg, 0.82 mmol) which was treated according to the method of Example 29 Step 2 to give 3-(bromomethyl)-2-fluoro-1-benzothiophene (95 mg, 12%). 1H NMR (500 MHz, CDCl3) δ 7.75 (1H, d, J=8.0 Hz), 7.68 (1H, d, J=8.0 Hz), 7.46 (1H, t, J=7.6 Hz), 7.39–7.35 (1H, m), 4.65 (2H, s).

Workup

  1. customThe solvent was removed in vacuo
  2. washwashed with sodium hydrogen carbonate solution, water and brine
  3. dry with materialdried over MgSO4
  4. customevaporated in vacuo
  5. customPurification by flash column chromatography on silica
  6. washeluting with isohexane

Sources & evidence

ORD record
ord-25fc685f89c34fc6805c7197facceebe
Source dataset
uspto-grants-2006_08
Patent number
US07094777B2

Linked notes

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