Water → Ethyl 5-butyl-α-oxo-2-thiopheneacetate

HRID 646234Notes

Reaction equation

HRID 646234 reaction equation
[CH2:1]([C:5]1[S:6][CH:7]=[CH:8][CH:9]=1)[CH2:2][CH2:3][CH3:4].[CH2:10]([O:12][C:13](=[O:19])[C:14](OCC)=[O:15])[CH3:11].O>C1C=CC=CC=1.Cl[Ti](Cl)(Cl)Cl>[CH2:10]([O:12][C:13](=[O:19])[C:14]([C:7]1[S:6][C:5]([CH2:1][CH2:2][CH2:3][CH3:4])=[CH:9][CH:8]=1)=[O:15])[CH3:11]

Participants

6

Reactant 3

HCID 962WaterHCID 7268Diethyl OxalateHCID 738182-n-Butylthiophene

Product 1

HCID 68697356Ethyl 5-butyl-α-oxo-2-thiopheneacetateYield 46.8%

Reagents, catalysts & solvents 2

HCID 24193Titanium TetrachlorideCatalystHCID 241BenzeneSolvent2×

Conditions

Temperature
5 °C

Procedure

To a 0° C. solution containing 2-butyl-thiophene (5 g, 35.6 mmol) dissolved in benzene (90 mL) and diethyloxalate (5.1 g, 35.6 mmol) was added (dropwise) a solution containing TiCl4 (6.7 g, 35.6 mmol) dissolved in benzene (10 mL). The reaction was let stir at 5° C. for 1 h then poured into water (300 mL) and extracted with ether. The organic layer was separated, washed with brine, then dried over MgSO4, filtered and stripped. The residue was purified by flash chromatography on silica gel in hexane/ethyl acetate 20:1. A yellow oil (4 g, 46% yield) was recovered. MS m/e 241 (M)+; 1HNMR (400 MHz, DMSO-d6 300 MHz) δ 0.9 (t, 3H), 1.4 (m, 5H), 1.6 (m, 2H), 2.9 (t, 2H), 4.4 (t, 2H), 7.1 (s, 1H), 7.9 (s, 1H).

Workup

  1. extractionextracted with ether
  2. customThe organic layer was separated
  3. washwashed with brine
  4. dry with materialdried over MgSO4
  5. filtrationfiltered
  6. customThe residue was purified by flash chromatography on silica gel in hexane/ethyl acetate 20:1

Sources & evidence

ORD record
ord-40b91c0d8b8d4888987e4893d6cdbd31
Source dataset
uspto-grants-2010_04
Patent number
US07705030B2

Reaction notes

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