1,2-Diaminocyclohexane → (S)-3-(2-methyl-1H-benzo[d]imidazol-6-yl)-4-phenyloxazolidin-2-one

Participants

Reaction Conditions

Reaction Steps

The compound was synthesized as trifluoroacetate salt starting from (S)-4-phenyloxazolidin-2-one (1 equiv., 0.163 g, 1 mmol), 4-iodobenzene-1,2-diamine (1 equiv., 0.234 g, 1 mmol), copper(I) iodide (0.1 equiv., 0.019 g, 0.1 mmol), cesium fluoride (2 equiv., 0.304 g, 2 mmol), cyclohexane-1,2-diamine (0.1 equiv., 0.012 mL, 0.1 mmol). The solids were given together in a reaction flask and the flask was purged with argon. A solution of cyclohexane-1,2-diamine in 4 mL dioxane was added to the flask. The reaction was stirred at 95° C. for 20 hours, before the reaction was cooled down to 45° C. and filtered through a pad of celite. The pad was washed with warm dichloromethane and the solution was concentrated under reduced pressure. The intermediate product was purified via FPLC using a chloroform-methanol gradient (0→10%, product elutes at about 5%). Yield: 0.215 g (80%); MS m/z 270.3 (M+H)+ The (S)-3-(3,4-diaminophenyl)-4-phenyloxazolidin-2-one was dissolved in 12 mL of triethyl orthoacetate and the reaction was stirred at 150° C. for 0.5 h before the reaction was cooled down. The excess of triethyl orthoacetate was removed under reduced pressure. The final product was purified by means of FPLC using chloroform-methanol gradient (0→10%), followed by preparative HPLC using a water-acetonitrile gradient with 0.04% trifluoroacetic acid.

Provenance & Evidence