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

반응식

Br[C:2]1[CH:3]=[C:4]([C:8]([O:10][CH:11]([CH3:13])[CH3:12])=[O:9])[S:5][C:6]=1[CH3:7].[Cu](C#N)[C:15]#[N:16].[C-]#N.[Na+]>CN(C)C=O>[C:15]([C:2]1[CH:3]=[C:4]([C:8]([O:10][CH:11]([CH3:13])[CH3:12])=[O:9])[S:5][C:6]=1[CH3:7])#[N:16]

참가 물질

실험 절차

A stirred solution of 1.9 g (7.3 mmol) of isopropyl 4-bromo-5-methylthiophene-2-carboxylate was dissolved in dry dimethylformamide (30 mL) and refluxed with copper cyanide (785 mg, 8.8 mmol) for 16 hours. The cooled solution was poured into 0.1 M aqueous sodium cyanide solution (300 mL) and extracted with diethyl ether (4×40 mL). The organic layers were washed with brine (2×40 mL), dried over anhydrous sodium sulfate, and the solvents removed in vacuo. Column chromatography on silica gel eluting with hexanes:ethyl acetate 9/1 (v:v), gave isopropyl 4-cyano-5-methylthiophene-2-carboxylate (960 mg, 63%) as a yellow crystalline solid 1H-NMR (DMSO-d6; 300 MHz) δ8.01 (s, 1H), 5.09 (septet, 1H, J=6.2 Hz), 2.67 (s, 3H), 1.29 (d, 6H, J=6.2 Hz).