To a suspension of diamine 1001 (400 mg, 1.56 mmol), 3-fluorophenylacetic acid (313 mg, 2.03 mmol), (R)-(−)-2,2-dimethyl-5-oxo-1,3-dioxolane-4-acetic acid (353 mg, 2.03 mmol) and Et3N (200 μL) in DMF (20 mL) at 0° C. was added HOBt (633 mg, 4.68 mmol) and followed by EDC (897 mg, 4.68 mmol). The mixture was stirred from 0° C. to room temperature over 18 h before it was diluted with water. The precipitate was collected by suction filtration and washed with water. The solid was further rinsed with a mixture of hot MeOH-THF. The combined filtrate was concentrated and purified by silica gel chromatography eluting with 1-10% MeOH in CH2Cl2 to provide (R)—N-(5-(4-(5-(2-(3-fluorophenyl)acetamido)-1,3,4-thiadiazol-2-yl)butyl)-1,3,4-thiadiazol-2-yl)-3,4-dihydroxybutanamide (1013, 93 mg).
