Triethylamine → Ethyl-4-cyano-7-[(3s)-3-(dimethylamino)pyrrolidin-1-yl]-5-methyl-6-phenyl-1,3-benzoxazole-2-carboxylate

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Reaction Conditions

Reaction Steps

Ethyl-4-cyan-7-fluoro-5-methyl-6-phenyl-1,3-benzoxazole-2-carboxylate 111) (200 mg, 0.62 mmol) was dissolved in dimethyl sulfoxide (12 ml), and at room temperature, triethylamine (112 μl, 0.80 mmol) was added. Next, the solution was heated at 150° C., and a solution of (3S)-3-(dimethylamino)pyrrolidine (94 μl, 0.74 mmol) dissolved in dimethyl sulfoxide (2 ml) was added all at a time, followed by further stirring for 1 hour. The mixture liquid was cooled to room temperature, then this was fractionated with ethyl acetate and saturated brine. The aqueous layer was separated, this was extracted twice with ethyl acetate. The organic layers were combined, washed with saturated brine, and dried over anhydrous sodium sulfate. The insoluble matter was separated by filtration, the solvent was evaporated away, and the resulting residue was purified by preparative TLC (eluent, chloroform:methanol=98:2) to obtain the entitled compound (17.5 mg, 7%) as a yellow powdery crystal.

Provenance & Evidence