Triethylamine → (S)-3-[3-[4-(1,1-dimethylethyl)phenyl]-1-oxopropyl]-4-(phenylmethyl)-2-oxazolidinone

Participants

Reaction Conditions

Reaction Steps

To a stirring solution at -78° C. of 4-(1,1-dimethylethyl)benzenepropanoic acid (1.29 g, 6.25 mmol) and triethylamine (1.05 mL, 7.51 mmol) in dry THF (26 mL) was added pivaloylchloride (0.77 mL, 6.25 mmol) dropwise. After the addition, the mixture was stirred at -78° C. for 10 minutes and at 0° C. for 30 minutes. During this time metalated oxozolidinone was prepared separately by dropwise addition of n-butyl lithium (4.29 mL of a 1.6M solution in hexane) to a solution of (S)-(-)-4-benzyl-2-oxazolidinone (1.23 g of 99% pure, 6.88 mmol) in dry THF (26 mL). The metalated oxazolidinone solution was then added, at -78° C., via a cannula to the previously prepared reaction mixture and stirred for 1 h at 0° C. The reaction was quenched at 0° C. by addition of saturated NH4Cl solution (16 mL) and was concentrated. Saturated NH4Cl solution (25 mL) was added to the residue and the mixture was extracted with CH2Cl2 (3×100 mL). The combined organic phases were washed with saturated NaHCO3 (100 mL) and dried (NaSO4). Filtration and concentration provided crude product (2.50 g) which was purified via flash chromatography, eluting with a mixture of EtOAc and hexane (1:3) to provide (S)-3-[3-[4-(1,1-dimethylethyl)phenyl]-1-oxopropyl]-4-(phenylmethyl)-2-oxazolidinone (1.82 g, 4.98 mmol) in 80% yield, mp 123°-126° C.

Provenance & Evidence