Diethyl Ether → 5-[2-(Benzo[b]thiophen-3-yl)ethenyl]thiophene-2-carboxaldehyde

HRID 1200051Notes

Reaction equation

HRID 1200051 reaction equation
Br[C:2]1[S:6][C:5]([CH:7]=[CH:8][C:9]2[C:10]3[CH:17]=[CH:16][CH:15]=[CH:14][C:11]=3[S:12][CH:13]=2)=[CH:4][CH:3]=1.C[CH2:19][O:20]CC.C([Li])CCC.CN(C)C=O>O>[S:12]1[CH:13]=[C:9]([CH:8]=[CH:7][C:5]2[S:6][C:2]([CH:19]=[O:20])=[CH:3][CH:4]=2)[C:10]2[CH:17]=[CH:16][CH:15]=[CH:14][C:11]1=2

Participants

6

Reactant 4

HCID 3283Diethyl Ether2×HCID 6228DimethylformamideHCID 53963715HCID 53963715, compoundHCID 178418339Butyllithium

Product 1

HCID 537352685-[2-(Benzo[b]thiophen-3-yl)ethenyl]thiophene-2-carboxaldehyde

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
-70 °C

Procedure

To a chilled (-70° C.), stirred solution of 3-[2-(5-bromo-2-thienyl)-ethenyl]benzo[b]thiophene (16.98 g) and ether (300 ml) was added n-butyllithium (23 ml of a 2.5M solution in hexanes), under nitrogen, over 5 mins. After stirring for 1.5 hrs, the mixture was added via canula to a solution of N,N-dimethylformamide (19.3 g) and ether (500 ml). The mixture was allowed to warm to room temperature, stirred overnight, and then poured into water (500 ml). The aqueous phase was separated, and the organic phase was washed with 10% aqueous hydrochloric acid, water, and 5% aqueous sodium bicarbonate solution. The solution was dried over anhydrous sodium sulfate, filtered, and concentrated to give 14.9 g of solid. A lot of similarly prepared material (4.1 g) was combined with the solid, and the combined material was purified by high performance liquid chromatography (silica gel, loaded and eluted with 10% hexane in dichloromethane). The appropriate fractions were combined and evaporated. The residue was recrystallized from toluene/hexane to give 9.25 g (51%) of product, mp 105°-107° C.

Workup

  1. temperatureto warm to room temperature
  2. stirringstirred overnight
  3. customThe aqueous phase was separated
  4. washthe organic phase was washed with 10% aqueous hydrochloric acid, water, and 5% aqueous sodium bicarbonate solution
  5. dry with materialThe solution was dried over anhydrous sodium sulfate
  6. filtrationfiltered
  7. concentrationconcentrated

Sources & evidence

ORD record
ord-34931859a64b4ec697808f58d6a60f13
Source dataset
uspto-grants-1990_02
Patent number
US04904674

Reaction notes

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