1-Ethyl-3-(3'-dimethylaminopropyl)carbodiimide → 3-(4-(1,3-dioxolan-2-yl)phenyl)-5-(1-(pyridin-2-yl)-5-(trifluoromethyl)-1H-pyrazol-4-yl)-1,2,4-oxadiazole

Participants

Reaction Conditions

Reaction Steps

To a solution of 1-(pyridin-2-yl)-5-(trifluoromethyl)-1H-pyrazole-4-carboxylic acid (31.46 g, 122 mmol) in DMF (200 mL) was added EDCI (23.34 g, 134 mmol) and HOBt (16.53 g, 122 mmol). After the reaction was stirred for 30 min. at room temperature 4-(1,3-dioxolan-2-yl)benzonitrile, Int.6-A, (16.53 g, 122 mmol) was added. The reaction mixture was stirred at 140° C. for 4 hr. The reaction mixture was concentrated under reduced pressure to remove the volatiles. The residue was partitioned between water and ethyl acetate and the organic layer was washed with aq. HCl solution, NaHCO3 solution, water, and brine before being dried over Na2SO4 and concentrated to provide 3-(4-(1,3-dioxolan-2-yl)phenyl)-5-(1-(pyridin-2-yl)-5-(trifluoromethyl)-1H-pyrazol-4-yl)-1,2,4-oxadiazole (25 g, 58 mmol). The compound had an HPLC retention time=6.15 min. −Column: HYPERSIL® BDS C18 (4.6×50 mm) Flow rate=0.8 mL/min. Solvent A=, 0.1% TFA in water; Solvent B=acetonitrile. 5%-100% B (0-6 min), 100% B (6-9 min), 100%-5% B (9-11 min). LC/MS M+1=430.0.

Provenance & Evidence