4-Ethylbenzoic Acid → 4-Ethylbenzoyl chloride

Participants

Reaction Steps

A mixture of 4-ethylbenzoic acid (0.50 g, 3.33 mmol) in SOCl2 (1 mL) and DMF(1 drop) was refluxed for 2 h. The reaction mixture was concentrated and then stripped with toluene (2×10 mL) to yield 4-ethylbenzoyl chloride (0.59 g, >100%) as a colorless oil. The crude acid chloride (0.59 g, 3.5 mmol) in toluene (minimum amount) was added dropwise to conc. aq. NH4OH (1.4 mL). After stirring for 1 h, the reaction mixture was concentrated, the residue was dissolved in water and extracted with EtOAc (3×25 mL). The combined organic layers were washed with 1 N aq. NaOH (10 mL) and brine and dried over Na2SO4 prior to removal of the volatiles to yield 4-ethylbenzamide (460 mg, 88%) as a white solid. A suspension of this crude amide (430 mg, 2.87 mmol) and LiAlH4 (180 mg, 4.7 mmol) in dry THF (5 mL) was refluxed at 65° C. for 4.5 h. More LiAlH4 (60 mg, 1.58 mmol) was added, and the reaction mixture was heated at 65° C. for 2 h. The reaction mixture was cooled, and 1 N aq. NaOH (0.4 mL) was added. After stirring for 4 h, the mixture was filtered, and the filtrate was concentrated to give 4-ethylbenzylamine (350 mg, 90w) as a pale yellow oil.

Provenance & Evidence