Sodium Cyanide → Isopropyl 4-cyano-5-ethylthiophene-2-carboxylate

HRID 2298637Notes

Reaction equation

HRID 2298637 reaction equation
Br[C:2]1[CH:3]=[C:4]([C:9]([O:11][CH:12]([CH3:14])[CH3:13])=[O:10])[S:5][C:6]=1[CH2:7][CH3:8].[Cu](C#N)[C:16]#[N:17].[C-]#N.[Na+]>CN(C)C=O>[CH2:7]([C:6]1[S:5][C:4]([C:9]([O:11][CH:12]([CH3:14])[CH3:13])=[O:10])=[CH:3][C:2]=1[C:16]#[N:17])[CH3:8]

Participants

5

Reactant 3

HCID 8929Sodium CyanideHCID 18536986Isopropyl 4-bromo-5-ethylthiophene-2-carboxylateHCID 178418260HCID 178418260, compound

Product 1

HCID 18537065Isopropyl 4-cyano-5-ethylthiophene-2-carboxylateYield 53%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

A stirred solution of 4 g (14.4 mmol) of isopropyl 4-bromo-5-ethylthiophene-2-carboxylate was refluxed in dry dimethylformamide (50 mL) with copper cyanide (1.94 g, 22 mmol) for 8 hours. The cooled mixture was poured into 0.1 M sodium cyanide (500 mL) and extracted with diethyl ether (4×50 mL). The organic layers were washed twice with brine (50 mL) and dried over anhydrous sodium sulfate. The solvents were removed in vacuo. Column chromatography on silica gel (400 g), eluting with hexanes:ethyl acetate 9/1 (v:v) gave isopropyl 2-ethyl-3-cyano-thiophene-5-carboxylate (1.7 g, 53%) as a pale yellow oil. 1H-NMR (DMSO-d6; 300 MHz) δ8.03 (s, 1H), 5.10 (septet, 1H, J=6.2 Hz), 3.04 (q, 2H, J=7.5 Hz), 1.31 (t, 3H, J=7.5 Hz), 1.30 (d, 6H, J=6.2 Hz). Mass spectrum (ESI m/z): Calcd. for C11H13NO2S 224.1 (M+H), found 224.0.

Workup

  1. extractionextracted with diethyl ether (4×50 mL)
  2. washThe organic layers were washed twice with brine (50 mL)
  3. dry with materialdried over anhydrous sodium sulfate
  4. customThe solvents were removed in vacuo
  5. washColumn chromatography on silica gel (400 g), eluting with hexanes

Sources & evidence

ORD record
ord-5893591dae844259955b8563adcc4d92
Source dataset
uspto-grants-2002_12
Patent number
US06492403B1

Reaction notes

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