Sulfuric Acid → 2-(1-Benzothiophen-5-yl)ethan-1-ol

HRID 553214Notes

Reaction equation

HRID 553214 reaction equation
O1CCCC1.[BH4-].[Na+].[S:8]1[C:12]2[CH:13]=[CH:14][C:15]([CH2:17][C:18](O)=[O:19])=[CH:16][C:11]=2[CH:10]=[CH:9]1.S(=O)(=O)(O)O>C1(C)C=CC=CC=1.O.CC(C)=O>[S:8]1[C:12]2[CH:13]=[CH:14][C:15]([CH2:17][CH2:18][OH:19])=[CH:16][C:11]=2[CH:10]=[CH:9]1

Participants

8

Reactant 4

HCID 1118Sulfuric AcidHCID 8028Tetrahydrofuran2×HCID 4311764Sodium borohydrideHCID 11469582Benzo[b]thiophene-5-acetic acid

Product 1

HCID 119833712-(1-Benzothiophen-5-yl)ethan-1-olYield 85.6%

Reagents, catalysts & solvents 3

HCID 180AcetoneSolventHCID 962WaterSolventHCID 1140TolueneSolvent

Procedure

To 340 mL of tetrahydrofuran was suspended 50.2 g of sodium borohydride, to which were dropped tetrahydrofuran (340 mL) solution of 170 g of (1-benzothiophen-5-yl)acetic acid, and 65.1 g of sulfuric acid successively, which was then stirred at room temperature for 2.5 hours. To this reaction mixture was dropwise added 85 mL of acetone, which was then stirred for 30 minutes. Thereto were added 510 mL of water and 680 mL of toluene. The organic layer was separated, to which was added 510 mL of water, and the pH was adjusted to 12 with 48 mL of 20% (w/w) sodium hydroxide aqueous solution. The organic layer was separated, and washed with water, followed by distilling off the solvent. Thereto were added cyclohexane and toluene. The precipitate was collected by filtration to provide 135 g of 2-(1-benzothiophen-5-yl)ethanol as white solid form.

Workup

  1. stirringwas then stirred for 30 minutes
  2. customThe organic layer was separated, to which
  3. additionwas added 510 mL of water
  4. customThe organic layer was separated
  5. washwashed with water
  6. distillationby distilling off the solvent
  7. additionThereto were added cyclohexane and toluene
  8. filtrationThe precipitate was collected by filtration

Sources & evidence

ORD record
ord-e293466984bb4d4184938ef19f57e46b
Source dataset
uspto-grants-2011_05
Patent number
US07951963B2

Reaction notes

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