Diisopropylethylamine → HCID 59597009, compound

Participants

Reaction Steps

Azetidine-1-carboxylic acid [4-(4-aminophenoxy)pyridin-2-yl]amide (108 mg) and 1-(4-fluorophenylcarbamoyl)cyclopropanecarboxylic acid (93.1 mg) were dissolved in N,N-dimethylformamide (4 ml), and diisopropylethylamine (0.363 ml) and HBTU (216 mg) were added under a nitrogen atmosphere at room temperature, followed by 3 hr. The reaction mixture was partitioned after addition of ethyl acetate (50 ml) and a saturated aqueous solution of sodium hydrogencarbonate (20 ml). The separated organic layer was washed with a saturated aqueous solution of sodium hydrogencarbonate (30 ml) and brine (30 ml), and dried over anhydrous sodium sulfate. The solvent was removed under reduced pressure, and the resultant residue was purified by silica gel column chromatography (eluent; heptane:ethyl acetate=1:7, then ethyl acetate). Fractions containing the target compound were concentrated under reduced pressure, and to the residue (106.2 mg) were added tert-butyl methyl ether (4 ml) and heptane (4 ml) to suspend a solid. The solid was collected by filtration, and dried under aeration to provide the roughly purified titled compound as pale yellow powder (87.5 mg). This was purified by silica gel column chromatography (eluent; heptane:ethyl acetate=1:7, then ethyl acetate). Fractions containing the target compound were concentrated under reduced pressure, and to the residue were added tert-butyl methyl ether (4 ml) and heptane (2 ml) to suspend a solid. The solid was collected by filtration, and dried under aeration to provide white powder. The powder obtained by filtration and the filtrate were combined, and purified by LC-MS. The solution containing TFA, acetonitrile and water was concentrated under reduced pressure, and to the residue was added a saturated aqueous solution of sodium hydrogencarbonate (50 ml), followed by stirring. The solvent was removed under reduced pressure, and the residue was partitioned after addition of ethyl acetate (100 ml). The organic layer was washed with a saturated aqueous solution of sodium hydrogencarbonate (50 ml) and brine (50 ml) in this order, and dried over anhydrous sodium sulfate. The solvent was removed under reduced pressure, and to the residue were added tert-butyl methyl ether and heptane to suspend a solid. The solid was collected by filtration, and derided under aeration to provide the titled compound as a white powder (16.3 mg, 8.79%)

Provenance & Evidence