Sulfuric Acid → 1-(2-Ethyl-butyl)-cyclohexanecarboxylic acid

Participants

Reaction Conditions

Reaction Steps

1-(2-Ethyl-butyl)-cyclohexanecarboxylic acid isopropyl ester (3.0 g, 11.8 mmol) was dissolved in ethylene glycol (48 mL). Powdered KOH (6.0 g, 107 mmol) was added and the mixture was stirred 42 h at 160° C. The cooled reaction mixture was slowly added to a stirred mixture of ice-water (120 mL) and 4M H2SO4 (40 mL), and extracted with DCM (2×120 mL). The organic phases were washed with diluted aq. NaCl until neutral, combined, dried over sodium sulfate and concentrated. The residue (2.5 g) was taken up in 4N NaOH and ice (30 g). The alkaline solution (pH 12) was extracted with TBME (40 mL). The TBME phase was washed twice with 4N NaOH/ice. The basic aqueous phases were made acidic to pH 1 using aq. H2SO4. Extraction with DCM (2×50 mL), washing with diluted aq. NaCl, drying over sodium sulfate and evaporation afforded 1.5 g (60%) 1-(2-ethyl-butyl)-cyclohexanecarboxylic acid, purity 94.1% (GC area, after derivatization with diazomethane).

Provenance & Evidence