Reaction #439827

Reaction equation

2-mercaptobenzoic acid

2-Ethyl-1-hexanol

2-mercaptobenzoic acid

sulfuric acid

→

2-ethylhexyl 2-mercaptobenzoate

Yield 95.4%

Solvents

water

water

water

toluene

Conditions

Workup

1. 1
   Otherequipped with a magnetic stirring bar
2. 2
   TemperatureAfter the mixture had been heated
3. 3
   Temperatureunder reflux
4. 4
   Washwashed in succession with 20 mL of saturated NaHCO3 solution and two 50-mL portions of brine
5. 5
   DryingThen the organic layer was dried over anhydrous MgSO4
6. 6
   Otherfreed of solvent by rotary evaporation under vacuum

Procedure

2-Ethyl-1-hexanol (21.0 g, 0.161 mol), 2-mercaptobenzoic acid (25.0 g, 0.162 mol), toluene (200 mL), and concentrated sulfuric acid (0.2 mL) were placed in a 500-mL three-neck round-bottom flask equipped with a magnetic stirring bar, a water separator, and a reflux condenser. After the mixture had been heated under reflux with stirring for 6 h, the solid 2-mercaptobenzoic acid had disappeared, and 2.90 mL (0.161 mol) of water had been collected by the water separator. The mixture was allowed to cool to room temperature and washed in succession with 20 mL of saturated NaHCO3 solution and two 50-mL portions of brine. Then the organic layer was dried over anhydrous MgSO4 and freed of solvent by rotary evaporation under vacuum to give 40.9 g (95%) of residual 2-ethylhexyl 2-mercaptobenzoate as a mobile straw-colored oil; 1H NMR (400 MHz, in CDCl3 w/TMS, ppm) 0.88-0.97 (m, 6H, 2CH3), 1.3-1.5 (m, 8H, 4CH2), 1.68-1.78 (m, 1H, CH), 4.21-4.29 (m, 2H, OCH2), 4.73 (s, 1H, SH), 7.1-7.3 [m, 3H, H-4 and H-5 with d (J=3.2 Hz) for H-3 at 7.29], 8.01 (d, J=7.6 Hz, H-6); {1H}13C NMR (100 MHz, in CDCl3 w/TMS, ppm) 166.99 (C═O), 138.49 and 126.39 (C-1 and C-2), 132.53, 131.77, 131.12, and 124.82 (C-3, -4, -5, and -6), 67.86, 39.19, 30.92, 29.33, 24.34, 23.35, 14.44, and 11.46 (8 aliphatic Cs).

Source