4,5,6,7-Tetrahydro-1-benzothiophene-3-carboxylic acid → 4,5,6,7-Tetrahydro-1-benzothien-3-ylmethanol

HRID 10223Notes

Reaction equation

HRID 10223 reaction equation
[S:1]1[C:5]2[CH2:6][CH2:7][CH2:8][CH2:9][C:4]=2[C:3]([C:10](O)=[O:11])=[CH:2]1.[H-].[Al+3].[Li+].[H-].[H-].[H-]>C(OCC)C>[S:1]1[C:5]2[CH2:6][CH2:7][CH2:8][CH2:9][C:4]=2[C:3]([CH2:10][OH:11])=[CH:2]1

Participants

4

Reactant 2

HCID 7677384,5,6,7-Tetrahydro-1-benzothiophene-3-carboxylic acidHCID 21226445Aluminium lithium hydride

Product 1

HCID 219783784,5,6,7-Tetrahydro-1-benzothien-3-ylmethanolYield 86.4%

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent2×

Procedure

A solution of 4,5,6,7-tetrahydro-1-benzothiophene-3-carboxylic acid (400 mg, 2.2 mmol) in diethyl ether (10 mL) was added under nitrogen to lithium aluminium hydride (1M solution in tetrahydrofuran, 3 mL, 3 mmol) in diethyl ether (10 mL) dropwise over 5 minutes. The reaction was stirred at room temperature for 1.5 hours then quenched with saturated ammonium chloride solution. The products were extracted into diethyl ether (x3). The combined organic layers were washed with water and brine, dried over MgSO4 and evaporated in vacuo to give 4,5,6,7-tetrahydro-1-benzothien-3-ylmethanol (320 mg, 86%). 1H NMR (500 MHz, CDCl3) δ 6.99 (1H, s), 4.56 (2H, s), 2.76 (2H, t, J=5.5 Hz), 2.58 (2H, t, J=5.6 Hz), 1.86–1.79 (4H, m), 1.43 (1H, s).

Workup

  1. customthen quenched with saturated ammonium chloride solution
  2. extractionThe products were extracted into diethyl ether (x3)
  3. washThe combined organic layers were washed with water and brine
  4. dry with materialdried over MgSO4
  5. customevaporated in vacuo

Sources & evidence

ORD record
ord-74d2a91588d34dd391817af6046327c9
Source dataset
uspto-grants-2006_08
Patent number
US07094777B2

Reaction notes

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