Trifluoroacetic acid → 2,3-Dimethyl-5-benzylthiophene

HRID 1069206Notes

Reaction equation

HRID 1069206 reaction equation
FC(F)(F)C(O)=O.[CH3:8][C:9]1[CH:10]=[C:11]([CH:15]([C:17]2[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=2)O)[S:12][C:13]=1[CH3:14].[BH4-].[Na+].[OH-].[Na+]>CCOCC>[CH2:15]([C:11]1[S:12][C:13]([CH3:14])=[C:9]([CH3:8])[CH:10]=1)[C:17]1[CH:18]=[CH:19][CH:20]=[CH:21][CH:22]=1

Participants

6

Reactant 4

HCID 6422Trifluoroacetic acidHCID 14798Sodium HydroxideHCID 4311764Sodium borohydrideHCID 116371262,3-Dimethyl-5-(alpha-hydroxybenzyl)thiophene

Product 1

HCID 102419632,3-Dimethyl-5-benzylthiophene

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent

Procedure

Trifluoroacetic acid (50 mL) was added dropwise over a 60 minute period to a stirred, 0° C. suspension of 4,5-dimethylthiophene-2-yl-(phenyl)-methanol (7.7 g, 35.3 mmol), sodium borohydride (6.67 g, 177 mmol) and ether (600 mL). After an additional 1.5 hours the reaction mixture was added to 10% aqueous sodium hydroxide (600 mL) and stirred for 30 minutes. The layers were separated and the ether phase was washed with 10% aqueous sodium hydroxide, brine and dried (magnesium sulfate). The ether phase was concentrated to provide the title compound as a an oil (6.73 g, 94%): NMR (CDCl3); δ7.33-7.19 (m, 5H), 6.47 (s, 1H), 4.03 (s, 2H), 2.27 (2, 3H), 2.06 (s, 2H); MS (EI) (M+) 202 (45%, MI).

Workup

  1. customThe layers were separated
  2. washthe ether phase was washed with 10% aqueous sodium hydroxide, brine
  3. dry with materialdried (magnesium sulfate)
  4. concentrationThe ether phase was concentrated

Sources & evidence

ORD record
ord-fac38840c49d449a821b58f9c8f96f20
Source dataset
uspto-grants-2001_06
Patent number
US06251936B1

Reaction notes

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