Sulfuric Acid → HCID 22186347, compound

Participants

Reaction Steps

To a 500-milliliter round-bottom flask equipped with a magnetic stirring bar, a water separator, and a condenser were added 27.23 grams (0.200 mol) of pentaerythritol, 90.22 grams (0.850 mol) of 2-mercaptopropionic acid, 100 milliliters of toluene, and 0.5 milliliter of concentrated sulfuric acid. The mixture was heated under reflux with stirring. After about 2 days, the solid material had disappeared, and about 17 milliliters (0.94 mol) of water had been collected by the water separator. Upon cooling to room temperature, the mixture was extracted with 30 milliliters of saturated NaHCO3 solution and washed with two 50-milliliter portions of water. The organic layer was dried over anhydrous MgSO4, and most of the toluene and residual 2-mercaptopropionic acid were removed by distillation under vacuum. Recrystallization of the residue from ethanol gave 86.0 grams (88.4%, calcd. 97.3 grams) of pentaerythritol tetrakis(2-mercaptopropionate) as a white solid, mp 93-96° C.; 1H NMR (in CDCl3 w/TMS, ppm): 4.17-4.30 (AB m, 8H, CH2O), 3.50 (pentuplet, 4H, CHSH), 2.17 (d of d, 4H, SH), 1.51 (d, 12H, CH3); {1H}13C NMR (in CDCl3 w/TMS, ppm): 172.79 (C═O), 62.47 (CH2O), 43.05 [C(CH2)4], 35.43 (CHSH), 20.94 (CH3).

Provenance & Evidence