Hydroxyamine hydrochloride → 4-Hexylthiophene-2-carbonitrile

Participants

Reaction Steps

A mixture solution of 4-hexylthiophene-2-carbaldehyde (11.8 g, 60.0 mmol) and hydroxylamine hydrochloride salt (6.3 g, 90 mmol) in pyridine/ethanol (60 mL, 1/1 v/v) was stirred at 80° C. overnight. Then the solvent was removed and the residue was dissolved in chloroform (100 mL). The solution was washed with distilled water (2×50 mL) and dried over anhydrous magnesium sulphate. The solvent was removed and the viscous liquid residue was refluxed in acetic anhydride (30 mL) containing potassium acetate (0.2 g) for 3 h. Then the mixture was poured into distilled water (100 mL) and extracted with hexanes (3×50 mL). The combined organic phase was washed three times with water (50 mL), dried over anhydrous magnesium sulfate before the solvent was removed by rotary evaporation. The yellow liquid residue was purified by silica-gel column chromatography (EtOAc/hexane=7/93, v/v, Rf=0.4) to yield a clear light yellow liquid product. (9.8 g, 84.5% yield). 1H NMR (400 MHz, CDCl3) δ (ppm): 7.43 (d, 1H, J=1.4 Hz); 7.17 (d, 1H, J=1.4 Hz); 2.60 (t, 2H, J=8.0 Hz); 1.59 (m, 2H); 1.22-1.36 (m, 6H); 0.87 (m, 3H). 13C NMR (100 MHz, CDCl3): δ 144.04, 138.22, 127.41, 114.48, 109.28, 31.45, 30.18, 29.86, 28.67, 22.46, 13.96. HRMS EI calcd for C11H15S 193.0925, found 193.0915.

Provenance & Evidence