p-Toluenesulfonic acid → 1-(2-Mercaptoethyl)-4-methylpyridinium p-toluenesulfonate

Participants

Reaction Conditions

Reaction Steps

To a suspension of p-toluenesulfonic acid (1.72 g, 0.01 mol) in benzene (6.5 mL) was added 4-picoline (1.17 mL, 0.012 mL). The resulting mixture was stirred under a nitrogen atmosphere at 23° C. for 30 min, treated with ethylenesulfide (0.65 mL, 0.011 mol) and stirred at 75° for 24 h. More ethylenesulfide (0.65 mL, 0.011 mol) was added and the stirring was continued at 75° C. for 24 h more. The reaction mixture was cooled to 23° C. and diluted with water (5 mL) and ether (8 mL). The aqueous layer was separated and washed with ether (3×8 mL). The traces of organic solvents were removed under vacuum and the compound was chromatographed on μ-bondapack C-18 with water as eluting solvent to give 2.94 g (90%) of the title compound as a colorless syrup; ir (film) θmax : 2510 (SH) 1640 (pyridinium), 1595, 1582, 1475, 1200 (sulfonate), 1031, 1010, 818 cm-1, 1Hmr (DMSO, d6) δ: 2.29 (3H, s, CH3 on pyridinium), 2.61 (s, CH3Ph), 2.4-2.8 (4H, SH, CH3Ph), 3.03 (2H, m[addition of D2O gave a t, J=6.4 Hz, at 3.04]CH2S), 4.68 (2H, t, J=6.4 Hz, CH2N+), 7.11, 7.49 (4H, 2d, J=7.9 Hz, Phenyl), 8.00 (2H, d, J=6.5 Hz, Bm of pyridinium), 8.89 (2H, d, J=6.5 Hz, Ho of pyridinium), uv (H2O) λmax : 256 (ε4315), 222 (ε17045)mμ.

Provenance & Evidence