Diisopropylethylamine → (3R,4R)-benzyl 3-(((S)-N-((R)-1-(5-benzyl-2-(2,5-difluorophenyl)thiazol-4-yl)-2,2-dimethylpropyl)tetrahydrofuran-2-carboxamido)methyl)-4-fluoropyrrolidine-1-carboxylate

Participants

Reaction Steps

The solution of (S)-(−)-2-tetrahydrofuroic acid (50 mg, 0.43 mmol) in thionyl chloride (0.5 mL) was refluxed for 30 min, and the volatile materials were completely concentrated in vacuo. The crude product was then dissolved in dichloromethane (0.3 mL), which was then added to a solution of (3R,4R)-benzyl 3-(((R)-1-(5-benzyl-2-(2,5-difluorophenyl)thiazol-4-yl)-2,2-dimethylpropylamino)methyl)-4-fluoropyrrolidine-1-carboxylate (40 mg, 0.066 mmol) and N,N-diisopropylethylamine (34 μL, 0.197 mmol). After the reaction mixture was stirred at room temperature overnight. The reaction mixture was quenched with saturated NaHCO3 solution and extracted with EtOAc. The organic layer was dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo. The crude product was purified by preparative reverse phase HPLC. The combined fractions of the product were neutralized with saturated NaHCO3 solution, which was then extracted with EtOAc. The organic layer was dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo to yield the desired (3R,4R)-benzyl 3-(((S)-N-((R)-1-(5-benzyl-2-(2,5-difluorophenyl)thiazol-4-yl)-2,2-dimethylpropyl)tetrahydrofuran-2-carboxamido)methyl)-4-fluoropyrrolidine-1-carboxylate (30 mg, 64.6%). LC/MS (uplc): MH+ 706.0, 1.40 min.

Provenance & Evidence