Cysteamine Hydrochloride → 2-[4-(2-Thienyl)phenyl]-1,3-thiazolane

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Reaction Steps

To a solution of 4-(2-thienyl)benzaldehyde (500.0 mg, 2.66 mmol) in EtOH (5.0 mL) was added a solution of cysteamine HCl (101.0 mg, 0.89 mmol) in water (2.0 mL) dropwise with stirring. The solution was then stirred at room temperature for 18 hours before the bulk of the EtOH was removed by rotary evaporator. The resulting residue was diluted with water (15.0 mL) and extracted with ether (3×30.0 mL) to remove excess aldehyde. The acidic aqueous layer was then basified with the slow addition of solid sodium carbonate (300.0 mg) to afford a white precipitate, which was filtered and washed carefully with water (3×20.0 mL). The solid was dried under reduced pressure to afford 2-[4-(2-thienyl)phenyl]-1,3-thiazolane (15) as a yellow powder (30 mg, 4.6%). 1H nmr (CDCl3, 300 MHz) 3.14, m, H4,4,5; 3.64, m, H5; 5.95, s, H2; 7.08, m, thienyl-H; 7.31, m, 2×thienyl-H; 7.50, d (8.1 Hz), 2×phenyl-H; 7.59, d (8.4 Hz), 2×phenyl-H. ESI (+ve) MS m/z 248 (M+H, 100%).

Provenance & Evidence