Diisopropylethylamine → HCID 90011400, compound

Participants

Reaction Steps

Step-5: 5-(1-(5-Bromopyridin-2-yl)-3-(trifluoromethyl)-1H-pyrazol-5-yl)-1,3,4-oxadiazol-2(3H)-one: To a stirred and (0° C.) cooled solution of step-4 intermediate (4.0 g, 11.43 mmol) and DIPEA (3.99 mL, 22.85 mmol) in DCM (50 mL) was added a solution of triphosgene (1.35 g, 4.57 mmol) in DCM (20 mL) over a period of 10 min. Reaction mixture was warmed to room temperature and stirred overnight. The reaction was cooled to 0° C. and quenched with ice water (5 mL). Water (25 mL) was added to the above mixture followed by DCM (100 mL). The layers were separated and the aqueous layer was extracted with DCM (2×100 mL). The combined organic layers were washed with brine (50 mL), dried (Na2SO4) and filtered. The filtrate was rotary evaporated to afford 3.0 g (70%) of the title compound as pink semisolid. 1HNMR (400 MHz, DMSO-d6) δ 12.95 (s, 1H, D2O exchangeable), 8.71 (d, J=2.5 Hz, 1H), 8.39 (dd, J=2.5 & 8.5 Hz, 1H), 7.90 (d, T=8.5 Hz, 1H), 7.70 (s, 1H); ESI-MS (m/z) 376, 378 [(MH)+, Br79,81].

Provenance & Evidence