Diisopropylethylamine → 3-Tert-butyl-5-(2-chloro-5-iodophenyl)-1,2,4-oxadiazole

Participants

Reaction Steps

To a solution of 2-chloro-5-iodobenzoic acid (1.0 g, 3.54 mmol) in 40 mL DMF was added diisopropylethyl amine (1.23 mL, 7.08 mmol) followed by HATU (2.02 g, 5.31 mmol). After stirring the reaction at room temperature for 10 min, N-hydroxy-2,2-dimethylpropanimidamide (0.82 g, 7.08 mmol) was added. The resulting reaction mixture was stirred at room temperature for 1 h and then at 110° C. for 16 h. After cooling to room temperature the reaction was quenched with water and extracted with ethyl acetate. The combined organic fractions were washed with brine, dried (Na2SO4), concentrated, and purified by flash chromatography (2-5% EtOAc in hexanes) to yield 660 mg of intermediate US1-2.

Provenance & Evidence