Diethyl Ether → 2-Ethyl-6-methylbenzoic acid

Participants

Reaction Steps

A 250 mL pressure bottle was charged with 2-ethyl-6-methyliodobenzene (30.07 mmol, 7.4 g), Pd(OAc)2 (1.43 mmol, 334 mg) and dppp (1.43 mmol, 620 mg). The flask was closed with a septum and evacuated three times with argon. Then, acetonitrile (96 mL), triethylamine (189 mmol, 19.0 g, 26.25 mL) and water (19.1 mL) were added successively by the aid of syringe. Then, the rubber septum was replaced with teflon lined cap connected to a carbon monoxide source. The flask was now pressurized with carbon monoxide (40 psi) and the excess pressure was released. This process was repeated three times and finally the mixture was stirred for 5 min under 40 psi carbon monoxide pressure. The flask was then disconnected from the carbon monoxide cylinder and immersed in a preheated oil bath (83-85° C.). The reaction mixture turned black in 1 hr and was stirred for another 14 hr at this temperature. Then, the reaction mixture was cooled to room temperature and the pressure was released. The resulting mixture was diluted with ether (200 mL) and 1.0N NaOH (20 mL). The formed acid was extracted into water (2×100 mL). The combined water extracts were neutralized with 1.0N HCl and the acid was extracted into dichloromethane (3×100 mL). The combined dichloromethane extracts were washed with brine solution and dried over MgSO4. Filtration of the drying agent and removal of solvent under vacuum gave 3.58 g (72.5%) of a viscous brown oil which slowly solidfied overnight. HR MS: Obs. mass. 164.0833. Calcd. mass. 164.0837 (M+).

Provenance & Evidence