1,3,4-Thiadiazol-2-amine → 3-cyclopentyl-2-(3,4-dichlorophenyl)-N-[1,3,4]thiadiazol-2-yl-propionamide

関与物質

反応手順

A solution of 3-cyclopentyl-2-(3,4-dichlorophenyl)-propionic acid (prepared as in Example 38A, 200.0 mg, 0.70 mmol), O-benzotriazol-1-yl-N,N,N′,N′-tetramethyluronium hexafluorophosphate (316.9 mg, 0.84 mmol), N,N-diisopropylethylamine (365 mL, 2.09 mmol), and 2-amino-1,3,4-thiadiazole (140.8 mg, 1.39 mmol) in dry N,N-dimethylformamide (2 mL) was stirred at 25° C. under nitrogen for 20 h. The reaction mixture was concentrated in vacuo to remove N,N-dimethylformamide. The resulting residue was diluted with ethyl acetate (100 mL). The organic layer was washed sequentially with a saturated aqueous sodium bicarbonate solution (1×50 mL), a 10% aqueous hydrochloric acid solution (1×100 mL), and a saturated aqueous sodium chloride solution (1×100 mL). The organic layer was dried over sodium sulfate, filtered, and concentrated in vacuo. Flash chromatography (Merck Silica gel 60, 230-400 mesh, 2/1 hexanes/ethyl acetate) afforded 3-cyclopentyl-2-(3,4-dichlorophenyl)-N-[1,3,4]thiadiazol-2-yl-propionamide (197.3 mg, 77%) as a white foam: mp 90-91° C.; EI-HRMS m/e calcd for C16H17Cl2N3OS (M+) 369.0469, found 369.0476.

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