Triethylamine → 2-cyclopropyl-5-methyl-7-[(3S)-3-(methylamino)pyrrolidin-1-yl]-6-phenyl-1,3-benzoxazole-4-carbonitrile

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Reaction Conditions

Reaction Steps

2-Cyclopropyl-7-fluoro-5-methyl-6-phenylbenzoxazole-4-carbonitrile (I-173) (250 mg, 0.86 mmol) was dissolved in dimethyl sulfoxide (5 ml), then at room temperature, triethylamine (155 μl, 1.11 mmol) and (3S)-3-(methylamino)pyrrolidine (119 μl, 1.11 mmol) were added. After stirred under nitrogen atmosphere at 90° C. for 13 hours, this was cooled to room temperature. The reaction liquid was fractionated with ethyl acetate and an aqueous saturated sodium hydrogencarbonate solution. The aqueous layer was further 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, then the solvent was evaporated away, and the resulting residue was purified by preparative TLC (eluent, chloroform:methanol=93:7, v/v) to obtain the entitled compound (201 mg, 63%) as a white solid.

Provenance & Evidence